CAIRO: The Arab League said it agreed on Sunday to open contacts with Syria's opposition and to ask the United Nations to form a joint peacekeeping force to the unrest-swept nation in moves swiftly rejected by Syria.

Arab diplomats "will open channels of communication with the Syrian opposition and offer full political and financial support, urging (the opposition) to unify its ranks," it said in a statement obtained by AFP.

They would also "ask the UN Security Council to issue a decision on the formation of a joint UN-Arab peacekeeping force to oversee the implementation of a ceasefire," it said.

After marathon talks in Cairo, the 22-member bloc also announced it had formally ended its own observer mission to Syria, suspended last month because of an upsurge in violence.

Only Algeria and Lebanon expressed reservations about the resolution, an Arab League official said.

Syria's ambassador to Cairo "categorically" rejected the Arab League moves.

"The Syrian Arab Republic categorically rejects the decisions of the Arab League," which "reflects the hysteria of these governments" after failing to get foreign intervention at the UN Security Council, Yusef Ahmed said in a statement.

On the ground, the Syrian Observatory for Human Rights reported that 14 people were killed in a relentless assault by President Bashar al-Assad's forces on the central protest city of Homs.

All but one of them died in Baba Amr, a rebel stronghold which armed forces have targeted for more than a week, killing at least 500 people, according to activists.

The Observatory also reported fierce clashes on the northern edge of nearby Rastan, where a woman was killed when a rocket hit her home. Elsewhere, snipers killed a child in Daraa, cradle of the 11-month uprising against Assad's regime.

"Tank and mortar fire intensified on Sunday afternoon," the Observatory's Rami Abdel Rahman told AFP, adding that the humanitarian situation was worsening.

As the military pressed its onslaught on Homs, refugees who fled from the city to Lebanon recounted the horrors they had witnessed.

"The army of Bashar al-Assad destroyed our homes," Abu Ibrahim told AFP. "Before, we were bombarded by mortars or rocket-propelled grenades, but now they are using tanks and helicopters."

Ibrahim said that his 10-year-old daughter Nada has refused food since seeing dead bodies littering the streets of the besieged city.

The Syrian Arab Red Crescent and International Committee of the Red Cross said their "volunteers are distributing food, medical supplies, blankets, and hygiene consumables to thousands of people" in Homs.

"We are greatly concerned about the consequences of the unrest from a humanitarian viewpoint and about the current deterioration of the situation," said the ICRC's Marianne Gasser.

"The population, particularly the wounded and sick, are bearing the brunt of the violence," she said in the statement.

UN chief Ban Ki-moon had broached the idea of a joint Arab-UN mission this month as he bemoaned the Security Council's failure to agree a resolution on the crisis in the face of Chinese and Russian opposition.

The Arab League has already put forward a plan for Assad to transfer power to his deputy and for a government of national unity to be formed ahead of elections.

On Sunday, Syrian government newspaper Ath-Thawra charged that Arab nations were in the pay of Western powers, accusations echoed by Syria's ambassador to Cairo.

The League's decision to back the opposition and call for a joint UN-Arab peacekeeping mission showed it was "hostage to the governments of (certain) Arab countries headed by Qatar and Saudi Arabia," working in collaboration with the West, Ahmed said.

Arab and western states will launch a bid at the UN General Assembly this week to put pressure on Assad after Saudi Arabia and Qatar drew up a resolution backing the League plan to end the crackdown.

The move follows the Russian and Chinese veto of virtually the same resolution in the Security Council eight days ago, and Moscow and Beijing are expected to oppose the new text.

No one can veto resolutions in the 193-nation General Assembly, though they carry less weight.

Syrian state television aired live footage on Sunday of an official funeral for the 28 people authorities say were killed in twin car bombs in the northern city of Aleppo on Friday.

The deputy foreign minister accused Arab and Western countries, which he did not name, of supporting the "terrorists" who carried out the attacks.

Damascus frequently blames foreign-backed "armed terrorist gangs" for the violence.

The rebel Free Syrian Army accused the regime of launching the Aleppo attacks "to steer attention away from what it is doing in Homs, Zabadani and elsewhere."

A US media report citing unnamed American officials said Al-Qaeda's Iraqi branch was likely to have carried out the bombings, along with attacks in Damascus in December and January.

Iraq's deputy interior minister, Adnan al-Assadi, told AFP Baghdad has "intelligence information that a number of Iraqi jihadists went to Syria" and that "weapons smuggling is still ongoing."

Al-Qaeda leader Ayman al-Zawahiri voiced his support for Syria's uprising in a new video posted on jihadist Internet forums, US monitors SITE Intelligence said.

Rights groups say more than 6,000 people have died since protests began in Syria in March last year, inspired by similar movements in Tunisia, Egypt and Libya.

Meanwhile, a commission tasked with drafting a new constitution submitted a draft charter to Assad, who will review it before referring it to the People's Assembly, the official SANA news agency reported.