MAREA - Syrian forces pounded rebel hubs in the northern city of Aleppo and battled opposition fighters around Damascus Friday, activists said, as the UN reported a surge in the number of people fleeing.

Violence was also reported in other towns and villages across the country, with the bloodletting showing no signs of any let-up a day after the United Nations formally called time on its observer mission.

Russia has called a meeting in New York Friday of UN ambassadors from the so-called Geneva action group on Syria but it was not clear whether Western governments - still angry at Moscow and Beijing for their vetoes of the UN resolutions - would attend.

However, adding to fears the fighting could ensnare Syria’s neighbours, the US warned its nationals they could be at risk in Lebanon, where the security situation is already fragile after a wave of kidnappings linked to Syria. On the ground, at least 72 people were killed as the regime continued its onslaught on Friday, according to the Syrian Observatory for Human rights, a watchdog which has a network of activists on the ground.

The army clashed with rebels near the main military airport in Damascus and shelled southern parts of the capital as well as areas of the commercial city of Aleppo and the eastern province of Deir Ezzor, the Observatory said.

Opposition factions also reported that 65 bodies had been found dumped on a rubbish tip in a town near Damascus, claiming the victims had been bound, executed and set on fire by pro-government forces.

The Syrian Revolutionary Command Council issued a very poor quality video which showed, some of the bodies were in just underwear or half-dressed, their limbs splayed apart, and hands tied behind their backs. Many were charred beyond recognition, piled haphazardly on top of one another amid the piles of trash. “The victims were handcuffed, extrajudicially executed and burned by Assad forces,” the SRGC said in a statement.

It is impossible to independently verify such claims as journalists are unable to report freely in Syria.

With the international community still deeply divided over how to end the conflict, the UN said the number of Syrians seeking refuge in neighbouring countries had now soared to at least 170,000.

“There has been a further sharp rise in the number of Syrians fleeing to Turkey,” the UN refugee agency said.

And French Foreign Minister Laurent Fabius called for President Bashar al-Assad’s regime to be “smashed fast” as he visited Turkey’s largest refugee camp near the border.

“After hearing the refugees and their account of the massacres of the regime, Mr Bashar al-Assad doesn’t deserve to be on this earth.” he said. “It is an operation of destruction of an entire people that he is trying to accomplish,” he said.

Residents of conflict zones are facing increasingly precarious situations, with shortages of food, fuel and medical supplies reported.

UN humanitarian chief Valerie Amos, who visited Damascus this week, warned that the number of people in need was as high as 2.5 million.

As the two sides become more entrenched in Syria, there are fears the conflict could spread further afield, after mass kidnappings in Lebanon in retaliation for events across the border.

The United States warned that its nationals face increased threats in Lebanon, including the possibility of targeted kidnappings or terrorist attacks, after several Gulf states ordered their nationals to leave.