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23 hostages reported dead as crisis in Algeria is 'brought to an end'

After the death of Western workers in an attack on a gas plant in the Sahara, Defense Secretary Leon Panetta vows to hunt down the militants responsible. NBC News' Annabel Roberts reports.

Twenty-three hostages and 32 militants were killed in the attack on a natural gas plant deep in the Sahara, the Algerian interior ministry said on Saturday, according to news services.

The official also said 107 foreign hostages and 685 Algerian hostages had been released, several news outlets reported.

Earlier, British Defense Secretary Philip Hammond said, speaking on information received by the British government, that the hostage crisis had "been brought to an end."

The militants took over the In Amenas plant on Wednesday, but Algeria's military launched a rescue attempt on Thursday.

The Algerian Press Service reported that a during a final attack by Algeria's military, the militants killed seven hostages, whose nationalities were not revealed. All of the remaining militants were reported killed.

At a joint press conference with U.S. Defense Secretary Leon Panetta, Hammond described the loss of life as "appalling and unacceptable."

"We remain in close contact with the Algerian government," Hammond said. "We remain determined to defeat terrorism and stand with the Algerian government."

Hammond said that the latest Algerian military operation had resulted in further loss of life. "We are pressing the Algerians for details on the exact situation and the numbers that have been killed and, if any, the numbers rescued," he said.

The Associated Press reported that around 100 of the 135 foreign workers on the site had been freed by Friday. The U.S. government confirmed Friday that one of the dead hostages was Frederick Buttaccio from Texas.

The militants claimed Friday that they were holding two American hostages and would exchange them for two people being held in the United States — the blind sheik Omar Abdel Rahman, convicted in the 1993 bombing of the World Trade Center, and Aafie Siddiqque, a 40-year-old Pakistani neuroscientist and mother of three, who was convicted of attacking U.S. soldiers in Afghanistan.

That would appear to account for all five Americans thought to have been at the plant, one U.S. official said, if the militants are telling the truth. 

In a statement Saturday, President Barack Obama said: "The blame for this tragedy rests with the terrorists who carried it out ... This attack is another reminder of the threat posed by al Qaeda and other violent extremist groups in North Africa." 

In a news release Saturday, British Prime Minister David Cameron said he feared for the lives of five British citizens who remained unaccounted for, Reuters reported.

Anis Belghoul / AP

Two British hostages -- Peter, left, and Alan, right (no family name available) -- are seen after being released, in a street near the gas plant where they were kidnapped by Islamic militants.

"One British citizen has already been killed in this brutal attack and we now fear the worst for the lives of five others who are not yet accounted for," Cameron said, according to Reuters.

British Petroleum said Saturday that four of its employees were among the hostages who remain missing.

In a conference call with reporters, Chief Executive Officer Bob Dudley said 14 of the 18 BP employees who were working at the site are “safe and secure” but four remain missing. Dudley said at this time he could not reveal the identities or nationalities of any of the employees. Dudley said the situation remains “very fluid and complex.”

Based on information from those hostages freed, Dudley said they suffered a “terrible and agonizing ordeal” and the situation inside the facility was “horrific.” Before “pre-judging” the actions taken by Algerian security Dudley said “we need he entire picture.”

The In Amenas plant, in a remote part of the Sahara Desert in eastern Algeria close to the Libyan border, is jointly run by BP, Norway's Statoil and Algeria's state-owned oil company.

The hostage standoff in Algeria is proving frustrating as both media and governments struggle for information. The Washington Post's Joby Warrick discusses the situation with MSNBC's Alex Witt.

Reuters and The Associated Press contributed to this report.

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