Syrian troops killed at least 62 rebels in an ambush near Damascus yesterday, the Syrian Observatory for Human Rights said.

The Syrian military said those killed were members of the jihadist Al-Nusra Front.

"At least 62 rebels fell as martyrs, most of them youths, and eight others are missing after an ambush by regime forces at dawn near the industrial city of Adra," northeast of the capital, the monitoring group said.

Meanwhile, Amnesty on Tuesday said the whole neighbourhoods of Syria's second city Aleppo have been flattened over the past year of conflict, with residents bombed from the air and abused on the ground.

“Aleppo has been utterly devastated, its people fleeing the conflagration in huge numbers," said Amnesty International's Senior Crisis Response Adviser Donatella Rovera.

The report came as the London-based group released satellite images of several Aleppo districts, taken before and after clashes between government and rebel forces broke out.

Amnesty also raised concern for Aleppo's ancient cultural sites, among them the damaged ancient souks and the destroyed minaret of the historic Umayyad mosque.