In this handout photo provided by the Shaam News Network, bodies of men whom activists said were killed by forces loyal to Syria's President Bashar Al-Assad are seen in Daraya near Damascus. REUTERS

A Syrian military helicopter has been shot down in Damascus, plummeting to the ground wreathed in smoke and flames.

Syrian rebels, who have been battling against the army in an ongoing uprising against the government of President Bashar al-Assad since March 2011, claimed responsibility for the attack.

Army helicopters and aircraft have recently been bombarding rebel-held districts in Damascus, renewing international criticism of the military's tactics, which have been attributed to causing thousands of civilian deaths over the course of the conflict.

Numerous massacres of civilians, including women and children, have occurred in various cities and towns in recent months, while attempts to investigate the killings by the UN human rights agency have been denied by the Syrian government.

Most recently, opposition forces claimed last to have discovered over 320 bodies of civilians murdered execution style in the town of Daraya, southwest of Damascus, following a military operation against the rebels.