At least 37 civilians were killed on Wednesday in Syrian Government air strikes near Damascus, while at least 13 people died as rebels fired a barrage of rockets into the capital, a monitor said.
The Syrian Observatory for Human Rights said at least four children were among the dead in regime strikes on the rebel-held Eastern Ghouta region, where some 120 people were also injured.
The death toll was likely to rise further, it said.
The air raids hit the towns of Douma, Saqba, Kafr Batna and Hammouriyeh in the rebel stronghold region outside the capital.
An AFP photographer in Douma saw more than a dozen bodies in makeshift plastic shrouds in a field hospital where medical
workers struggled to aid the wounded.