Footage on Youtube showed bodies piled up wall-to-wall in a mosque complex in Daraya. The attack on Daraya was part of an army campaign to regain control of the outskirts of the capital. Activists say Syrian forces with tanks and combat helicopters also launched fresh raids in other cities.

At least 320 corpses were found on Saturday and Sunday, the victims of a five-day onslaught by the army on rebel fighters in Daraya, the Syrian Observatory for Human Rights said, according to AFP.

The Local Coordination Committees,  said Assad’s forces killed 440 people across Syria on Saturday. The organization, which monitors Assad’s military crackdown, said 310 people were killed in Damascus and its environs, including Daraya, 40 in the northern province of Aleppo and 28 in Syria’s Sunni tribal heartland region of Deir al-Zor, according to Al Jazeera. The rest were reportedly killed in the Idlib, Deraa, Hama and Homs.

Meanwhile, Syrian State television reported that Daraya had been  ”purified of terrorists”. 
President Bashar al-Assad has blamed foreign-backed terrorists for much of the violence that has gripped his nation for nearly the past 18 months.

The fresh violence erupted a day after new international envoy Lakhdar Brahimi admitted he was “scared” of the enormity of the task he faces to end the 18 month conflict.

The UN estimates that more than 18,000 people have been killed since the uprising against Assad’s government began in March 2011.