Valery Hache / AFP - Getty Images

Investigators are trying to track down 50 suspected Auschwitz guards who are believed to be living in Germany. The gate at the former Nazi death camp, which is located in Poland, reads "Arbeit macht frei" -- or "work will set you free."

MAINZ, Germany -- In their search for justice that has endured for decades, the biggest challenge Nazi hunters face is time. 

The knowledge that war criminals are escaping prosecution through death by natural causes means their task has never been more pressing.

On Monday, German state police arrested a 93-year-old man accused of being a guard at the Auschwitz concentration camp. Hans Lipschis is the first suspect to be facing charges as part of a drive launched earlier this year to track down 50 suspected Auschwitz guards who are believed to be living in Germany.

Most of those involved in the murder of about 6 million Jews in the Holocaust and still alive will now be in their 90s, a ripe old age for people who carried out one the most heinous crimes in the history of humanity.

But that doesn't stop Kurt Schrimm, director of Germany’s Central Investigation Center for Nazi Crimes. His agency employs 20 people, including seven focusing on the Auschwitz cases. 

"Someday there will be no more Nazi criminals to go after and then our organization will shut down," he said. "But until then, we will exhaust all investigation possibilities."

After years of frustration, Nazi hunters have also been given fresh hope by a German court's landmark ruling that has made it simpler to prosecute cases by opening the door to charges of "accessory to murder."

Efraim Zuroff, Israel director of the Simon Wiesenthal Center in Jerusalem, said he planned to ask German companies to help fund a renewed campaign to find the remaining war criminals and take advantage of the ruling, which came during the successful prosecution of John Demjanjuk.

Demjanjuk, an autoworker who lived in the U.S. for years after the war, was convicted in 2011 of 28,060 counts of being an accessory to murder and sentenced to five years in prison.

Although he died a free man in a nursing home in Germany – he was released pending his appeal – the court’s ruling that he could be convicted on his service record alone was “a total game-changer,” Zuroff said.

“Until that point … German prosecutors could not try a case unless they had evidence of a specific crime with a specific victim,” he said.

“Demjanjuk was convicted solely for his service as an armed SS guard at a death camp,” he added. “As a result, this opened up a whole new potential number of people to bring to justice.”

Valery Hache / AP

Convicted Nazi death camp guard John Demjanjuk leaves a courtroom after a guilty verdict in Munich, Germany, on May 12, 2011.

Zuroff said there were usually three obstacles to holding Nazi war criminals to account: Finding them; getting enough evidence; and persuading the authorities to act.

The Demjanjuk ruling changed that in Germany.

“Now in Germany, all of a sudden, all you have is one task – all you have to do is find people, because you can prove service with documents,” Zuroff said. “You don’t have to have someone who says, ‘I saw this bastard kill my fellow inmate.’”

Schrimm said that the Demjanjuk case prompted his agency to start "looking at old files with a renewed focus."

He added: “Today, any job in a concentration camp can be sufficient evidence towards a conviction as accessory to murder."

It is a ray of hope in an otherwise gloomy picture. 

“Once the Nuremberg Trials had been completed [in 1949], the prosecution of Nazi war criminals never became a serious priority in any country outside of the Soviet Union,” Zuroff added. “The failure to do more to hold the perpetrators of the Holocaust accountable is naturally a source of frustration and disappointment for me personally, as someone who has devoted practically my entire adult life to that mission."

The Holocaust saw approximately 6 million Jews – about two-thirds of the pre-World War II Jewish population in Europe – murdered to fulfill Adolf Hitler’s infamous “Final Solution.”

Roma Gypsies, Slavic people such as Poles and Russians, communists, socialists, disabled people, Jehovah’s Witnesses, homosexuals and others were also slaughtered in large numbers.

Zuroff said that no one really knew how many people were involved in the killings, let alone how many were still alive.

But, asked to estimate, he reckoned that “probably not more than 10 to 15 percent” of tens of thousands of Nazi war criminals had been brought to justice.

The Simon Wiesenthal Center publishes an annual “most wanted” list, and also rates countries based on their willingness to take action. Only the United States got the top rating in 2013; Germany was among five countries in the second-highest group.

Zuroff said that “to their credit” Germany was one of the few countries that would bring prosecutions.

In contrast Austria, which became part of the Hitler’s Third Reich in 1938, was “horrific, terrible, the worst,” Zuroff said.

“They haven’t succeeded in taking action against a Nazi war criminal in more than 30 years. It’s not because there are no Nazis in Austria,” he said. “There’s a country that until 20 years ago … got away with claiming they were Hitler’s first victim. Austrians played a very leading role in the murders carried out by the Third Reich.”

Zuroff said it was “impossible” to get prosecutions in the Baltic countries, “especially in Lithuania.”

“They were the worst because they had a vast number of collaborators,” he said. “They don’t like punishing their own people and would prefer to think of themselves as victims of communism and not killers of Jews, which they were. They were outstanding killers of Jews.”

Avner Shalev, chairman of Yad Vashem, Israel’s official memorial to victims of the Holocaust, said the survivors "live with the memories every day."

"Bringing the perpetrators to justice sends an important educational and moral message to society at large: These kinds of crimes will not be tolerated, and there are no free passes," he said. "Although unfortunately many of the perpetrators escaped justice, nevertheless each trial sends an important message."

Germany and its allies controlled most of Europe during World War II, including Norway, France, Italy, Greece, the Balkans, Poland and deep into the then Soviet Union.

Lydia Brenners was just 9 years old when she was caught up in a horrific massacre of Jews in Novi Sad in modern-day Serbia by Hungarian forces in 1942. Nazi-allied Hungary had annexed the area in 1941.

Brenners said she was forced to go to with her father, mother and sister to a local theater where many Jewish people were being gathered. They were taken in groups to the banks of the River Danube, where they were shot dead. A total of more than 1,200 civilians are thought to have been killed, according to The Associated Press.

“Slowly we came nearer and nearer [to the end of the line],” said Brenners, now 81 and living in Rishon Letzion, Israel. “Today I know it was for killing. Then … I didn’t know, maybe the older people understood.”

“In the row behind me, there was an auntie of one of my girlfriends. I knew her. She was holding a baby in her hands,” she said. “After a few minutes … [she] burst out with nerves and started to shout, ‘I cannot bear it anymore.’”

“The soldiers came and took her,” she said, despite efforts of others who surrounded her in an unsuccessful attempt to save her. “She did not come back from there.”

But then came an order from Budapest to stop the killing and Brenners and her family were released. They then took the train to Budapest that day and hid in the city until it was taken by Soviet troops toward the end of the war.

Brenners said years later she met a woman who said she was the child of her friend’s aunt. The woman was still trying to find out how she survived.

Brenners said she remembered an officer on a horse -- who was addressed as “Shanny” -- overseeing the massacre and the gendarmes referring to lists of names when deciding who should be taken.

She said “Shanny” was a nickname for Sandor Kepiro, a gendarme officer accused of helping organize the killings.

Kepiro was given a 10-year prison sentence over the Novi Sad massacre by a Hungarian court in 1944, but this was overturned after Germany formally occupied Hungary later that year, according to The Associated Press.

Kepiro, who lived in Argentina after the war, admitted he was present and supervised the identities of those being rounded up, but denied knowing they were killed until later, the news service said.

Kepiro was tried again in Hungary but acquitted in 2011, with a court ruling there was insufficient evidence against him, the AP reported. The prosecution appealed, saying the judges’ decision was “unfounded,” and so did the defense, which complained the ruling had not actually cleared Kepiro.

However, Kepiro died in September 2011, an innocent man in the eyes of the law, a hero to some in Hungary, but a killer who escaped justice to Zuroff and his fellow Nazi hunters.

Ian Johnston reported from London. The Associated Press contributed to this report.

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Lisi Niesner / Reuters

Survivor Petro Mischtschuk, 87, from Ukraine, wears his old prisoner's garb as he stands near the memorial site of the Little Camp at Buchenwald.

Between July 1937 and April 1945, the Nazis imprisoned a quarter of a million people in the Buchenwald concentration camp, located near the German city of Weimar. Around 56,000 of them were killed before the camp was liberated by U.S troops on April 11, 1945.

68 years later, Reuters photographer Lisi Niesner interviewed some of the remaining survivors as they returned to Buchenwald to mark the anniversary of the liberation.

Lisi Niesner / Reuters

Victor Karpus, 88, from Ukraine, stood at the muster ground where inmates gathered at dawn each day for a roll call. Karpus was imprisoned in several camps including Buchenwald for a total of three years. He even once managed to escape from a camp but got captured and taken to Buchenwald, where he remained until its liberation.

"Work or die – it was impossible to get out from Buchenwald," Karpus says.

Lisi Niesner / Reuters

Lisi Niesner / Reuters

"To each his own": An inscription on Buchenwald's iron gate.

Eva Pusztai, 88, from Hungary, sat in a wheelchair in front of a reconstructed gallows. In July 1944 she was deported to Birkenau and six weeks later to Muenchmuehle, one of 136 satellite camps of Buchenwald.

The forced labor in the arms industry or the camp's stone quarry took the imprisoned to the brink of their physical abilities. "You got just enough food to survive. I lost a third of my weight and I was almost starving to death," she says. 

"The employable have to be destroyed by work," she says, explaining the attitude of the Nazis to their prisoners. Her right eye filled up with a single tear that ran down her cheek, then she composed herself and smiled.

Lisi Niesner / Reuters

"Where is your god? Why he does not help you?" Jakob Silberstein, born in Poland in 1924, remembers the mocking of a high-level Nazi on Yom Kippur. He survived six years of captivity in Buchenwald and Auschwitz and witnessed brutal actions by the SS, being locked in a standing cubicle for a week, carrying stones and drinking rainwater for days. 

He was standing inside the gas chamber at Birkenau when an SS man asked if any of the men were skilled laborers. "I stated I was an electrician, which luckily saved my life," he said. After the liberation he found out that none of his family or friends had survived the war. He now lives in Israel and tirelessly tells his story.

Lisi Niesner / Reuters

Lisi Niesner / Reuters

Urns are displayed in a room adjacent to the crematorium at Buchenwald.

Professor Elling Kvamme, 94, from Norway, stood at the site of Barrack Block 22. He was teaching medicine at a university in Oslo in 1943 when he was arrested for his connections with underground politics. "Students are always dangerous and the Nazis realized it very quickly," he explained.

He was forced to take part in the Nazi program of Germanization and had to work at the pathological facility in Buchenwald. Before the dead were cremated in an incineration system developed to veil the traces of murder, specimens were taken from their corpses for anatomical collections.

Lisi Niesner / Reuters

Vasile Nussbaum, 83, from Romania, spent a year in Auschwitz and Buchenwald. "Buchenwald was a sanatorium in comparison to Auschwitz" he recalls without hesitation.

Nussbaum revisits the site of the camp every year on liberation day. "You never know what’s coming, today we are 83 years old and in the next year we are no more here", he says.

Lisi Niesner / Reuters

Barracks behind trees at Buchenwald.

Editor's note: Pictures taken between April 11-14, 2013 and made available to NBC News today. Read more at Reuters' Photographers Blog.

Courtesy Auschwitz Jewish Center

The Chevra Lomdei Mishnayot synagogue (c. 1939-1941).

REGENSBURG, Germany -- A synagogue near the former Nazi death camp Auschwitz is on the verge of collapse, officials warned on Wednesday.

The head of the Auschwitz Jewish Center Foundation, which maintains the historic building in the southern Polish city of Oswiecim, said in a phone interview that the synagogue is on unstable ground and if it is not reinforced soon, it may crumble.

"There are already small cracks visible," Tomasz Kuncewicz said. "A thorough examination found that the ground is unstable and with heavy rain or something similar, anything can happen."

If the Chevra Lomdei Mishnayot Synagogue were to collapse, the only surviving Jewish house of prayer in the city would be ruined.

Oswiecim, once an ordinary town home to a large Jewish community, became an international symbol of the Holocaust when Nazi Germany ran its largest and deadliest concentration camp just two miles from the city center during World War II. Some 1.5 million people, mostly Jews, were killed at the Auschwitz-Birkenau camps.

"Several synagogues were located in the area, and this was the only one not destroyed by the Nazis," Kuncewicz said.

Jacek Bednarczyk / EPA

Students visit the Chewra Lomdei Mishnayot Synagogue in Auschwitz, Poland, on Wednesday.

The synagogue itself seems to trace the tragic path of the Jewish community in the area.

Built around 1913, it thrived until the Nazi occupation. During World War II, the interior was gutted and it was used to store ammunition.

After the war and the liberation of the concentration camp, a group of Jewish survivors restored the building provisionally, but it stopped operating when the small group emigrated from Poland shortly thereafter. In the 1970s, the country's communist government nationalized the building and turned it into a carpet warehouse.

It wasn't until 1998 that the synagogue was turned back over to the Jewish community, a historic first in Poland after the fall of the communist regime in 1989. It was rededicated in 2000 in an effort to rekindle the Jewish community that had been so vibrant in the city decades before.

Today, it is not only a place of prayer, but also a historical site and educational center that draws 25,000 visitors each year.

Organizers are seeking $300,000 for the renovation effort, the majority from donations, but they also are asking for help from government agencies.

Kuncewicz said he hoped to start the repairs this spring: "We are working very hard to raise money for this project, to make sure the synagogue will stand."

BERLIN, Germany -- Israeli Zeev Avrahami stands in the small kitchen of his restaurant peeling eggs and dripping fresh olive oil on a plate of hummus he is about to serve. The restaurant's name -- 'Sababa,' which is slang for good or fun -- is written proudly in Hebrew letters over its entrance.

Nearly 70 years after the Holocaust was planned and executed in the German capital and Nazi atrocities nearly extinguished Jewish life on the European continent, Avrahami's eatery is a sign of a new chapter of Jewish life in Germany.

Avrahami is at the culinary forefront of an influx of Israelis who have moved Berlin in recent years. Officials at the Israeli Embassy estimate that about 15,000 of its citizens now live in the city, thought to be the highest number in decades.

'They don't know what to say'
Before the Holocaust about 160,000 Jews called Berlin home. By the time the city was liberated by the Red Army in 1945, only 8,000 remained. 

And while Avrahami feels safe in Berlin, his interactions with German citizens are often burdened by the past.

"Once you say you're Israeli, there is silence. They don't know what to say," he told NBC News. "In Germany, it's still hard to be different, a foreigner. It's not an immigration country, it's not America."

What is attracting young Israelis to the former center of Nazi Germany? Even today, synagogues, Jewish schools, and other buildings linked to the community across Germany are under constant police protection amid fears of attacks by right-wing and Islamist groups.

Carlo Angerer / NBC News

The Sababa restaurant in central Berlin is a small sign of a new chapter of Jewish life in Germany.

Israeli insurance salesman Ilan Weiss, who moved to Berlin in 1990, believes the increasing cost of living and cuts to social services in his homeland -- as well as Berlin's image as a hip and multicultural destination -- is behind the trend.

Weiss, who runs the the non-profit IsraelisinBerlin.de website, said that some new arrivals "show up with only a suitcase."

"I get requests from new arrivals or Israelis looking to move to Berlin nearly every week," Weiss added. "It’s hard to live in the country where they come from, so the people come to Germany, where it's better than the rest of Europe, even than the U.S."

Economic woes
Among the incomers is Inbal Mayan, who came to Berlin about 4 months ago. The 31-year-old Tel Aviv native says daily life in her homeland has become difficult to afford for many young Israelis, even if they work two or three jobs.

Mayan says that even though Berlin is famous for its easy-going lifestyle, the economy is a key factor for many Israelis. "It's not about the partying anymore, but it's about life that you can actually live and afford and not to struggle every day to have money, to live a simple life," she said. "In Israel you must struggle, you struggle every day."

More Germany coverage from NBCNews.com

She now takes German courses at the local Jewish community's language school and hopes to attend university and get a Master’s degree.

Fellow language student Bar Ben-Yehuda arrived one-and-a-half years ago from the outskirts of Jerusalem.

"Here we have the opportunity for a better life, we can build something," he said. "The opportunities are better here than in Israel – I’m very sad to say this, because that's my country, but it’s the truth."

But sooner or later, Berlin's dark past creeps in as reminders of Jewish life destroyed by the Holocaust are evident throughout the city, from the massive Holocaust memorial to so called 'Stolpersteine' (stumbling blocks), commemorative metal plaques installed in front of former homes of Jews deported to concentration camps.

'You have to deal with it'
Restaurant owner Avrahami, who has been living in Berlin for four years, says the German capital becomes a spirital place for many Israelis.

"A lot of arrivals, because they're so young, they don't see that but there is something that pulls you down," he told NBC News. "At the beginning you don’t pay attention to the signs, but it creeps in you all the time. At some point you have to deal with it."

More Israel coverage from NBCNews.com

Israeli Nirit Bialer, 34, moved to Berlin six years ago and helped to start the group Habait, 'home' in Hebrew, hopes to bring Germans and Israelis together through cultural events and creating a place for enhanced dialogue between the two groups.

Young Germans tend to be not as preoccupied with the burden of the country's dark past as their parents' generation.

"Berlin is a very cosmopolitan city," Bialer says. "It's not necessarily this gray dark place that we are taught from history." 

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Johannes Simon / Getty Images, file

John Demjanjuk emerges from a Munich court after a judge sentenced him to 5 years in prison on May 12, 2011.

BERLIN -- John Demjanjuk, a retired U.S. autoworker who was convicted of being a guard at the Nazis' Sobibor death camp despite steadfastly maintaining over three decades of legal battles that he had been mistaken for someone else, died Saturday, his son told The Associated Press. He was 91.

Demjanjuk, convicted in May of 28,060 counts of being an accessory to murder and sentenced to five years in prison, died a free man in a nursing home in the southern Bavarian town of Bad Feilnbach. He had been released pending his appeal.

John Demjanjuk Jr. said in a telephone interview from Ohio that his father died of natural causes. Demjanjuk had terminal bone marrow disease, chronic kidney disease and other ailments.

It was not yet known whether he would be brought back to the U.S. for burial.

Ukrainian-born Demjanjuk had steadfastly denied any involvement in the Nazi Holocaust since the first accusations were levied against him more than 30 years ago.

"My father fell asleep with the Lord as a victim and survivor of Soviet and German brutality since childhood," Demjanjuk Jr. said. "He loved life, family and humanity. History will show Germany used him as a scapegoat to blame helpless Ukrainian POWs for the deeds of Nazi Germans."

His conviction helped set new German legal precedent, being the first time someone was convicted solely on the basis of serving as a camp guard, with no evidence of being involved in a specific killing.

Presiding Judge Ralph Alt said the evidence showed Demjanjuk was a piece of the Nazis' "machinery of destruction."

"The court is convinced that the defendant ... served as a guard at Sobibor" from March 27, 1943, until mid-September 1943, Alt said in his ruling.

Israeli Holocaust scholar Yehuda Bauer, who researches at the Yad Vashem memorial, said Demjanjuk's story showed an important moral lesson.

"You don't let people, even if they were only junior staff, get away from responsibility," Bauer said.

Despite his conviction, his family never gave up its battle to have his U.S. citizenship reinstated so that he could live out his final days nearby them in the Cleveland area. One of their main arguments was that the defense had never seen a 1985 FBI document, uncovered in early 2011 by the AP, calling into question the authenticity of a Nazi ID card used against him.

Demjanjuk maintained that he was a victim of the Nazis himself -- first wounded as a Soviet soldier fighting German forces, then captured and held as a prisoner of war under brutal conditions.

"I am again and again an innocent victim of the Germans," he told the panel of Munich state court judges during his 18-month trial, in a statement he signed and that was read aloud by his attorney Ulrich Busch.

He said after the war he was unable to return to his homeland, and that taking him away from his family in the U.S. to stand trial n Germany was a "continuation of the injustice" done to him.

"Germany is responsible for the fact that I have lost for good my whole reason to live, my family, my happiness, any future and hope," he said.

But representatives of victims, Jewish groups and others welcomed his trial as a legitimate quest for justice.

"A death is always tragic. But in this case it is important to say that it was right to put him on trial and sentence him," the president of Germany's Central Council of Jews, Dieter Graumann, told the AP.

"Justice does not know a statute of limitation, and age does not protect from punishment. This was never about revenge, but about justice," he added.

Demjanjuk's claims of mistaken identity, however, gained credence after he successfully defended himself against accusations initially brought in 1977 by the U.S. Justice Department that he was "Ivan the Terrible" -- a notoriously brutal guard at the Treblinka extermination camp.

In connection with the allegation, he was extradited to Israel from the U.S. in 1986 to stand trial on charges of war crimes and crimes against humanity, convicted and sentenced to death. But the Israeli Supreme Court in 1993 overturned the verdict on appeal, saying that evidence showed another Ukrainian man was actually "Ivan the Terrible," and ordered him returned to the U.S.

The Israeli judges said, however, they still believed Demjanjuk had served the Nazis, probably at the Trawniki SS training camp and Sobibor. But they declined to order a new trial, saying there was a risk of violating the law prohibiting trying someone twice on the same evidence.

Demjanjuk returned to his suburban Cleveland home in 1993 and his U.S. citizenship, which had been revoked in 1981, was reinstated in 1998.

Demjanjuk remained under investigation in the U.S., where a judge revoked his citizenship again in 2002 based on Justice Department evidence suggesting he concealed his service at Sobibor.

Appeals failed, and the nation's chief immigration judge ruled in 2005 that Demjanjuk could be deported to Germany, Poland or Ukraine.

Prosecutors in Germany filed charges in 2009, saying Demjanjuk's link to Sobibor and Trawniki was clear, with evidence showing that after he was captured by the Germans he volunteered to serve with the fanatical SS and trained as a camp guard.

Though there are no known witnesses who remember Demjanjuk from Sobibor, prosecutors referred to an SS identity card that they said features a photo of a young, round-faced Demjanjuk and that says he worked at the death camp. That and other evidence indicating Demjanjuk had served under the SS convinced the panel of judges in Munich, and led to his conviction.

He was ordered tried in Munich because he lived in the area briefly after the war.

Demjanjuk, who was removed by U.S. immigration agents from his home in suburban Cleveland and deported in May 2009, questioned the evidence in the German case, saying the identity card was possibly a Soviet postwar forgery.

He reiterated his contention that after he was captured in Crimea in 1942, he was held prisoner until joining the Vlasov Army -- a force of anti-communist Soviet POWs and others formed to fight with the Germans against the Soviets in the final months of the war.

Demjanjuk was born April 3, 1920, in the village of Dubovi Makharintsi in central Ukraine, two years before the country became part of the Soviet Union. He grew up during a time when the country was wracked by famines that killed millions, and a wave of purges instituted by Stalin to eliminate any possible opposition.

As a young man Demjanjuk worked as a tractor driver for the area's collective farm. After being called up for the Soviet Red Army, he was wounded in action but sent back to the front after he had recovered, only to be captured during the battle of Kerch Peninsula in May 1942.

After the war, Demjanjuk was sent to a displaced persons camp and worked briefly as a driver for the U.S. Army. In 1950, he sought U.S. citizenship, claiming to have been a farmer in Sobibor, Poland, during the war.

Demjanjuk later said he lied about his wartime activities to avoid being sent back to Ukraine, then a part of the Soviet Union.

Just to have admitted being in the Vlasov Army would also have been enough to have him barred from emigration to the U.S. or many other countries.

He came to the U.S. on Feb. 9, 1952, and eventually settled in Seven Hills, a middle-class suburb of Cleveland.

He was a mechanic at Ford Motor Co.'s engine plant in the Cleveland suburb of Brook Park and with his wife, Vera, raised three children -- son John Jr. and daughters Irene and Lydia.

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Updated 5:20 p.m. ET: The world marked International Holocaust Remembrance Day on Friday with a promise never to forget the genocide at Auschwitz during World War II.

Friday was the 67th anniversary of the Nazi camp's liberation by Soviet troops. Jan. 27 was designated as International Holocaust Remembrance Day by the United Nations in 2005, and marked with ceremonies across Europe.

In Poland, Kazimierz Smolen, a 91-year-old Auschwitz survivor who after World War II became director of the memorial site, died Friday on the anniversary of its liberation.

Smolen died in a hospital in Oswiecim, the southern Polish town where Nazi Germany operated Auschwitz-Birkenau during World War II, said Pawel Sawicki, a spokesman for the Auschwitz-Birkenau state museum.

Sawicki said soon after Smolen's death the news was announced to Holocaust survivors who had gathered at the vast site of dilapidated barracks still enclosed in barbed-wire fencing, The Associated Press reported. They fell silent for a minute in his honor.

Smolen was born on April 19, 1920, in the southern Polish town of Chorzow Stary. He was a Pole involved in the anti-Nazi resistance who was arrested by the Germans in April 1941 and taken to Auschwitz in one of the early mass shipments of prisoners there. He left the camp on the last transport of prisoners evacuated by the Germans on Jan. 18, 1945, nine days before its liberation. He later attributed his survival to good health and extreme luck.

He once explained his decision to return to the camp to manage it as a way of honoring those who were killed there.

"Sometimes when I think about it, I feel it may be some kind of sacrifice, some kind of obligation I have for having survived," he said.

In other gestures of remembrance, Norway's Prime Minister Jens Stoltenberg apologized for his nation's role in arresting and deporting Jews after it was invaded by Nazi Germany. During the war, 772 Norwegian Jews and Jewish refugees were deported to Germany. Only 34 survived.

He said it's time the nation acknowledges that politicians and other Norwegians took part and expressed "our deep regrets that this could have happened on Norwegian soil." He spoke at a ceremony in Oslo attended by the last surviving Jew in a group of 532 deported from Norway in 1942.

In Turkey, state television on Thursday broadcast the epic French documentary "Shoah," about the mass murder of Jews under the German Nazi regime. It was the first time the film has been aired on public television in a predominantly Muslim country.

"It is a historical event," filmmaker Claude Lanzmann, 87, said in a telephone interview with The Associated Press from his home in Paris. "It is extremely important that it is being shown in a Muslim country."

Germany's Parliament also gathered Friday for a special sitting to remember the Holocaust.

Prominent survivor and literary critic Marcel Reich-Ranicki recalled how the Nazi SS informed members of the Warsaw ghetto's Jewish council in July 1942 of plans for the inhabitants' "resettlement" to the east.

Reich-Ranicki, 91, recounted how a "deathly silence" was followed by uproar. He said those present "seemed to sense what had happened: that the sentence had been pronounced for the biggest Jewish city in Europe. The death sentence."

The Nazis set up the Warsaw ghetto in November 1940, cramming hundreds of thousands of Jews into inhuman conditions. Most who survived disease and starvation in the ghetto were transported to death camps.

The Associated Press contributed to this report.