DAMASCUS, Jan 20, 2012: Pressure mounted on the Arab League on Friday to seek UN intervention in the face of growing exasperation that the bloc's hard-won observer mission in Syria has failed to staunch 10 months of killing.

Despite widespread criticism of the mission, its deputy chief of operations, Ali Jarush, told reporters that it was likely to be extended by a month.

The head of the mission on the ground, General Mohammed Ahmed Mustafa al-Dabi of Sudan, is preparing to report to Arab foreign ministers, who are to meet on Sunday in Cairo to discuss the next step.

"Everything indicates that the observer mission in Syria will be extended by a month, since the first month has not been enough as part of it was taken up by logistic preparations," Jarush said in the Egyptian capital.

Human Rights Watch said the observers' presence had failed to rein in the Syrian regime's crackdown, with activists reporting 506 civilians killed and another 490 detained since the monitors first deployed on December 26.

It urged the regional bloc "to publicly recognise that Syria has not respected the League's plan and work with the Security Council to increase pressure on the authorities and effectively curtail the use of fire power."

The head of the opposition Syrian National Council, Burhan Ghaliun, headed to Cairo to lobby Arab ministers to refer the observer mission's findings to the UN Security Council for tough action.

Ghaliun planned to ask the League "to transfer the file on Syria to the UN Security Council with a view to securing a decision to establish a buffer zone and a no-fly zone" in Syria, an SNC statement said.

The SNC said it would demand that Dabi pull no punches in his findings on Damascus's compliance with the Arab League agreement.

"The SNC delegation will insist that the report contain a clear text concerning the 'genocide' and 'war crimes' carried out by the (Syrian) regime against unarmed civilians," the statement said.

An SNC spokesman told AFP in Cairo that the group is "preparing a counter report" to the one Dabi is due to submit to the pan-Arab body.

Mohammed Sermini said the SNC report would cover the situation in Syria during the month-long mission of the Arab observers.

Meanwhile, Ahmad el-Tayyeb, the grand imam of Cairo's Al-Azhar, the highest seat of Sunni Muslim learning, urged "Arab rulers to take the necessary measures to halt bloodshed in Syria," Egypt's state news agency MENA reported.

And Syrian protesters gathered outside the Russian embassy in Cairo to vent their anger over Moscow's support for President Bashar al-Assad's regime, an AFP correspondent said.

A tough Security Council resolution on Syria has been blocked by veto-wielding permanent members China and Russia. Moscow insists the opposition is as much to blame for the violence as the regime.

Deadlock in the Security Council over Syria has raised the stakes of an Arab solution to the crisis.

"Many Arab countries have rejected the idea of sending Arab troops to Syria" in line with a suggestion by Qatar, an Arab League official who declined to be identified said in Cairo ahead of Sunday's meeting of Arab foreign ministers.

The official also noted that Damascus -- which has slammed Qatar's proposal -- favours extending the mission for another month, and said "the number of monitors will be increased to some 300."

French Foreign Minister Alain Juppe said the Qatari proposal to send peacekeepers was not feasible "in the present regional context," in an interview published by the regional daily Ouest-France.

"On the contrary, we are talking to the opposition," he added.

But President Nicolas Sarkozy insisted that France -- the former colonial power in Syria -- would not stand silently by in the face of a crackdown that the United Nations estimates has killed more than 5,400 people since March.

"We cannot accept the ferocious repression by the Syrian leadership of its people, a repression that has led the entire country into chaos, and a chaos that will help extremists of all kinds," he said.

In Syria, thousands of people poured out of mosques after Friday prayers to call for the ouster of Assad's regime, after choosing "Prisoners of the Revolution" as the slogan for this week's main protests.

They are demanding that the government deliver on its promise to the Arab League to release tens of thousands of people arrested since protests first erupted in March.

The Syrian Observatory for Human Rights said security forces came out in force and opened fire on protesters in flashpoint areas on Friday, killing at least five civilians.

In Bernex in eastern France, meanwhile, the funeral took place on Friday of French television journalist Gilles Jacquier, who was killed on January 11 in the central Syrian city of Homs during a press trip organised by the authorities.