SYRIAN government warplanes supported by Russia continued their bombardment of the rebel-controlled eastern suburbs of Damascus for a sixth day, killing five people, activists said.

The death toll from the past week climbed to more than 400, with the casualties overwhelming rescuers and doctors at hospitals, many of which have also been bombed.

This fresh bombardment comes a day after world leaders called for an urgent ceasefire in Syria to allow relief agencies to deliver aid and evacuate the critically wounded from besieged areas.

However, Russia’s UN ambassador Vassily Nebenzia, who called Thursday’s meeting, put forward last-minute amendments, saying the proposed resolution was “simply unrealistic”. A new vote was expected to be held yesterday.

The US accused Syrian president Bashar Assad of planning “to bomb or starve” opponents in besieged eastern Ghouta into submission – just as it did in Aleppo.

Kelley Currie, US ambassador for economic and social affairs, told the UN Security Council that the Syrian leader is counting on Russia, a key ally and veto-wielding member of the council, to make sure it “is unable to stop their suffering”.

The opposition’s Syrian Civil Defence Rescue Group reported new airstrikes in Douma, Arbeen and other towns that make up the eastern suburbs of Damascus known as eastern Ghouta.