Syrian government forces have unleashed dozens of rockets and air strikes on the besieged rebel area of Eastern Ghouta since late Friday when the United Nations delayed a vote on a possible ceasefire.
At least 140 rockets were launched overnight at different areas of Eastern Ghouta on the outskirts of Damascus, the Syrian Observatory for Human Rights reported on Saturday.
Government jets carried out a series of raids early on Saturday on the rebel-controlled suburbs, killing at least three civilians and injuring 12 in Eastern Ghouta's town of Harsta, the observatory's head Rami Abdel-Rahman, told dpa.
The latest deaths bring to 474 the number of civilians that the Britain-based watchdog estimates to have been killed in government attacks in Eastern Ghouta since Sunday.
In recent weeks, the forces of Syrian President Bashar al-Assad have intensified attacks on Eastern Ghouta.
On Friday, the UN Security Council had to postpone until Saturday a vote on a resolution drafted by Kuwait and Sweden proposing a 30-day ceasefire throughout Syria to allow for the delivery of humanitarian aid and evacuation of critically ill people.
The delay was due to last-minute changes demanded by Russia, a major ally of al-Assad, according to diplomats at the UN.
Russia has concerns that there is no guarantee militants would adhere to any ceasefire and demanded amendments to the draft.
Previous truce attempts have failed to hold in Syria.
Australian Associated Press
