A video reportedly shot by an amateur in the Syrian city of Idlib Wednesday shows a crippled Syrian military helicopter spiraling down before it explodes in flames. Syrian rebels say they shot down the helicopter, according to The Telegraph.

The rebels reportedly have acquired heavy weapons in recent weeks, The Telegraph reported, pushing the Syrian air force to attack rebel-held zones from higher altitudes.

Syria's divided rebels have agreed to set up a joint leadership to oversee their battle to overthrow President Bashar Assad, two insurgent sources said Tuesday as fighting raged in cities across the country.

Rebels hope the decision, taken after increasing pressure from foreign supporters on them to unite, will help convince those backers that they are a credible and coordinated fighting force deserving to be supplied with more powerful weapons.

'Extremely dangerous': Assad forces use cluster bombs as rebels gain, rights group says

"The agreement has been reached, they only need to sign it now," one rebel source said. Foreign supporters "are telling us: 'Sort yourselves out and unite, we need a clear and credible side to provide it with quality weapons.'"

He said Qatar and Turkey were the main drivers behind the agreement, which he added might be formally announced this month.

Since the beginning of the revolt against Assad, Western powers have been reluctant to arm the divided rebel factions.

This is the latest attempt to bring together Assad's disparate armed opponents, most of whom have fought nominally under the banner of the rebel Free Syrian Army but who in practice have operated independently, often weakened by deep rivalries.

More weapons in Syria could trigger 'all-out war'

The new leadership will include FSA leaders Riad al-Asaad and Mustafa Sheikh - criticized by many rebels because they are based in Turkey - and recently defected Gen. Mohammad Haj Ali, as well as heads of rebel provincial military councils inside Syria like Qassem Saadeddine, based in Homs province.

Slideshow: Syria uprising

Fabio Bucciarelli / AFP - Getty Images

A look back at the violence that has overtaken the country.

Launch slideshow

The Syrian National Council has set Nov. 4 as the date for an opposition unity conference in Qatar, organizers said.

The 19-month-old revolt against Assad, which started as peaceful demonstrations, has mushroomed into a civil war, pitting the mainly Sunni Muslim rebels against a power structure dominated by the Alawite minority.

Activists say more than 30,000 people have been killed, hundreds of thousands have fled to neighboring countries and more than a million have been displaced inside Syria as entire city districts have been rendered ghost towns by heavy shelling.

The British Observatory for Human Rights said 80 people had been killed in Syria by dusk on Tuesday, after 160 died on Monday. Heavy clashes broke out in the city of Hama, and fighting continued in Aleppo and the northern province of Idlib.

A Reuters correspondent on Lebanon's northeastern border with Syria saw a helicopter dropping explosives on the Syrian side of the frontier. Refugees unloading blankets from a pickup truck in an olive grove on the Lebanese side stopped to watch big black plumes of smoke rising into the sky.

Underlining increasing international concern about the conflict, Pope Benedict will send a group of top cardinals to visit Syria in coming days to express solidarity with its battered population, the Vatican news service said.

Envoy seeks ceasefire
U.N.-Arab League mediator Lakhdar Brahimi has called on Shiite Muslim Iran, Assad's closest regional ally, to help arrange a ceasefire in Syria during the Islamic holiday of Eid al-Adha later this month.

Diplomatic sources said Brahimi is also trying to persuade Assad and the rebels to accept a ceasefire and allow U.N. monitors into the country to oversee it.

Brahimi, who took over after Kofi Annan quit in frustration in August, has been traveling around the Middle East trying to nudge regional powers into accepting his plan, which resembles a ceasefire Annan tried in vain to implement, U.N. diplomats said.

But diplomatic sources familiar with Brahimi's proposals said that neither Assad's government nor the fractious opposition had shown interest in halting the conflict.

Major powers at the United Nations remain deadlocked over what to do to defuse Syria's conflict.

Outgunned rebels have struggled to turn the tide of conflict against government forces endowed with tanks, jets and helicopter gunships. But Western powers have been reluctant to arm the insurgents because they perceive no coherent leadership and fear that weapons are ending up in the hands of Islamist militants increasingly evident in the conflict.

Mistrust and miscommunication have dominated relations between rebel brigades and each privately accuse the other of incompetence. Differences over leadership, tactics and sources of funding have also widened rifts between largely autonomous brigades scattered across Syria.

The rebel sources said countries who have supported the revolt but whose own rivalries have exacerbated rebel divisions agreed that it was time the rebels fight side by side.

"There will never be unity inside Syria unless the countries supporting the revolt agree because each group is supported and backed by (one) country," one source said.

"Now the countries are becoming nervous and the Syrian issue has become bigger than they expected and almost out of control."

Rebel leaders believe a common fighting front would enable coordination of multifaceted operations crucial to success against a better armed adversary.

"If a brigade wants to hit a (government) checkpoint,  then an intelligence unit would check it out and then raise a report up to the (regional) command. The command will take a decision on the number of men needed for this operation and the kind of weapons plus other issues," another rebel source said.

Reuters contributed to this report.

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Bulent Kilic / AFP - Getty Images

Syrian refugees arrive at the Turkish border at Reyhanli in Antakya, Wednesday.

A dramatic increase in the numbers of Syrian refugees fleeing President Bashar Assad's regime was reported Thursday, as his forces appeared to have routed the opposition in at least two key cities.

On the anniversary of the uprising, the opposition appeared to be in disarray, with The New York Times reporting that several prominent members of the main opposition exile group, the Syrian National Council, had resigned, claiming it was autocratic and dominated by the Muslim Brotherhood faction.

The Times, which headlined its article "Syria Opposition Group Is Routed and Divided," said that the government's takeover of the cities of Homs and Idlib was near complete, fueling frustration among the rebels.

"What happened in Homs is betrayal,"  Kamal al-Labwani, a respected dissident who has resigned, told the paper. "There is a sense of irresponsibility on the part of the council."

Country music, Chris Brown, Harry Potter: Leaked emails reveal tastes of Syria's Assad

On the ground, Assad’s forces pressed home their military advantage, appearing to step up the offensive against rebel strongholds, sending tanks into the southern town of Deraa, where the rebellion began on March 15, 2011, after people were appalled by the torture of children over anti-Assad graffiti.

Official media announced government forces had cleared "armed terrorists" from the northwestern city of Idlib. However, there were reports of continuing clashes in areas around Idlib, as well as close to the central city of Homs.

The Turkish official said there had been a sharp increase in the flow of people fleeing the country, bringing the total number of registered Syrian refugees in Turkey to some 14,000.

"Around 1,000 people crossed the border from Syria to Turkey in the last 24 hours," the official said. "We expect this to continue as long as the operation goes on in Idlib."

Amid dire warnings that Syria is sinking into a protracted civil war, the U.N.-Arab League envoy Kofi Annan has demanded further clarification from Damascus over its response to proposals aimed at ending the violence.

He is due to report back to a divided U.N. Security Council on Friday. Russia and China remain behind a defiant Assad while exasperated Western powers push for regime change.

The United Nations estimates that more than 8,000 people, mostly civilians, have died in the fighting. Some 230,000 Syrians have been displaced from their homes, including 30,000 who have fled abroad, raising the prospect of a refugee crisis.

Syrian forces had pounded Idlib with artillery in recent days before sending in troops to regain control of the city, which had been a bastion for the Free Syria Army -- a disparate collection of lightly armed militants led by deserters.

"Security and peace of mind returned to the city of Idlib after authorities cleared its neighborhoods of armed terrorist groups which had terrorized citizens," the state news agency Sana reported on Thursday.

Report: Leaked emails indicate Syria president got advice from Iran

The British-based Syrian Observatory for Human Rights said pockets of resistance remained in Idlib.

"The army has control of the main streets but not the alleyways and side roads," said Rami Abdulrahman, who relies on a network of Syrian residents for his information.

Reports from Syria cannot be independently verified as the authorities deny access to rights groups and journalists.

Syrian state television said there would be a "Global March for Syria" to honor those killed by the rebels and video footage showed crowds gathering in a central Damascus square.

The government has blamed foreign powers and "terrorists" for the chaos and say 2,000 soldiers have died in the conflict.

Deraa quiet on anniversary
Assad confidently predicted at the start of 2011 that Syria was immune from the "Arab Spring", in which the autocratic leaders of Tunisia, Egypt, Libya and Yemen were swept from power.

But on March 15, a few dozen protesters braved the streets of Damascus to call for more freedom. Days later riots broke out in Deraa, on the border with Jordan, to protest against the torture of local boys caught writing anti-government graffiti.

A contact in Deraa told Reuters most schools and shops in the main commercial area were closed on Thursday, with hundreds of security forces patrolling the streets. State employees were being ordered to stage a pro-Assad rally, residents said.

Despite a crumbling economy and tightening sanctions, Assad still seems to have significant support within Syria, notably in its two top cities -- Damascus and Aleppo. Its main ally Iran also remains supportive.

Diplomats say the fighting is developing along sectarian lines. The Sunni Muslim majority, who make up 75 percent of the population of 23 million, is at odds with Assad's Alawite sect, which represents 10 percent but controls the levers of power.

Other minorities, such as the Christians, are sticking with Assad for fear of reprisals should he be ousted, analysts say.

"The strategy of the regime is civil war, after it failed to silence the people. So it's trying to protect its future by moving toward dividing the country," said Najati Tayyara, a veteran dissident and Sunni liberal who has fled to Jordan.

Reuters contributed to this report.

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Rodrigo Abd / AP

Women and children take shelter from fierce fighting between the Free Syrian Army and government troops in Idlib, north Syria, on Saturday.

Updated 12:15 p.m. ET: BEIRUT -- U.N.-Arab League envoy Kofi Annan said it would be hard to reach a deal to halt bloodshed in Syria, but expressed optimism after meeting President Bashar al-Assad for a second day on Sunday.

"It's going to be tough. It's going to be difficult but we have to have hope," he told reporters in Damascus.

"I am optimistic for several reasons," Annan said, citing a general desire for peace in Syria. "The situation is so bad and so dangerous that all of us cannot afford to fail."

Khaled Al-Hariri / Reuters

U.N. envoy Kofi Annan, left, and Syria's Foreign Minister Walid al-Moualem enter a restaurant to attend a working lunch in Damascus on Saturday.

The former United Nations chief, who is from Ghana, said: "I have urged the president to heed the African proverb which says: 'You cannot turn the wind, so turn the sail.' "

Annan, speaking before departing for Qatar, said he had left "concrete proposals" with Assad for a way out of a conflict that has cost thousands of lives.

"You have to start by stopping the killings and the misery and the abuses that are going on today, and then give time (for a) political settlement," he said.

There was no immediate word from Syrian officials on the outcome of the talks, but Assad told Annan on Saturday that "terrorists" spreading chaos and instability were blocking any political solution, according to the state news agency SANA.

But it said the 46-year-old president had also told Annan he would help in "any honest effort to find a solution".

Syrians involved in a popular uprising against Assad say there can be no meaningful dialogue with a leader who has inflicted such violence and suffering on his own people.

"Him (Assad) stepping down is definitely a first condition of any discussion or negotiation," Bassma Kodmani of the opposition Syrian National Council told the BBC on Sunday.

The United Nations says Assad's forces have killed more than 7,500 people in a year-long crackdown on protesters and insurgents. Authorities say rebels have killed 2,000 soldiers.

Annan's mission has coincided with a Syrian military offensive against opposition strongholds in the northwest.

Reuters

Activists said at least four people were killed in the town of Idlib on Sunday after troops and tanks moved in a day earlier. Three soldiers and a civilian were also killed in fighting in the village of Janoudiya in Idlib province on Sunday morning, according to the Syrian Observatory for Human Rights.

State news agency SANA said "terrorists" shot dead a former boxing champion, Ghiath Tayfour, in the city of Aleppo and also killed a leading Baath Party member in Homs province.

The Observatory said 39 civilians, including 25 in Idlib province, were killed on Saturday, along with 39 rebels and 20 government soldiers, giving an overall death toll of 98.

Russian Foreign Minister Sergei Lavrov, who met Annan in Cairo on Friday, told the Arab League his country was "not protecting any regime," but did not believe the Syrian crisis could be blamed on one side alone.

He called for a ceasefire and humanitarian aid access, but Qatar and Saudi Arabia sharply criticized Moscow's stance.

Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani, who has led calls for Assad to be isolated and for Syrian rebels to be armed, said a ceasefire was not enough. Syrian leaders must be held to account and political prisoners freed, he declared.

Saudi Foreign Minister Saud al-Faisal said shortcomings in the U.N. Security Council, where Russia and China have twice vetoed resolutions on Syria, had allowed the killing to go on.

Their position, he said, "gave the Syrian regime a license to extend its brutal practices against the Syrian people."

Saudi Arabia and Qatar, which are both ruled by autocrats and espouse a strict version of Sunni Islam, are improbable champions of democracy in Syria. Riyadh has an interest in seeing Assad fall because this could weaken its Shi'ite regional rival Iran, which has been allied with Syria since 1980.

Syria opposition chief rejects UN peace talks

International rifts have paralyzed action on Syria, with Russia and China opposing Western and Arab calls for Assad, who inherited power from his father nearly 12 years ago, to quit.

The United States has drafted a fresh U.N. Security Council resolution, but Washington and Paris have said they are not optimistic it will be accepted.

Despite their differences, Lavrov and Arab ministers said they had agreed on the need for an end to violence in Syria.

They also called for unbiased monitoring of events there, opposition to foreign intervention, delivery of humanitarian aid and support for Annan's peace efforts.

But the exiled opposition Syrian National Council ruled out talks while Assad is in power.

"Negotiations can never take place between the victim and torturer: Assad and his entourage must step down as a condition before starting any serious negotiations," it said.

U.S. Secretary of State Hillary Clinton will meet Lavrov in New York on Monday when the Security Council holds a special meeting on Arab revolts, with Syria likely to be in focus. 

Syrian forces have been building up for days around Idlib, the capital of a hilly, agricultural province along the Syria-Turkey border that has been a hotbed of protests against Assad's regime.

Saturday morning, troops blasted Idlib for hours with dozens of tank shells as the forces moved to encircle the town, an Associated Press team in Idlib reported.

Families fled their homes, carrying blankets and a few other meager belongings. Others huddled in homes.

'I join the revolution': 1st senior Assad official defects

The Idlib operation raised fears that Assad is set to launch an all-out offensive in Idlib like the one that captured captured part of Homs in the south.

Reuters and The Associated Press contributed to this report.