Days of government bombardment in rebel-held eastern Ghouta has now left more than 500 people dead, observers fear.

Nearly 130 children and 75 women are among those killed in ongoing airstrikes on the Syrian suburb which began last Sunday.

Bombing on Saturday killed at least 22 people and left dozens wounded.

Earlier this week, a UN official described the people of eastern Ghouta as living "in hell on earth", but Syria's ambassador to the UN denied the Assad regime was killing its own people.

The latest bombardment comes after the UN Security Council delayed a vote on Saturday on a resolution demanding a 30-day humanitarian cease-fire across Syria.

Syrian opposition activists claim Russian warplanes are also taking part in bombarding eastern Ghouta, a suburban area of the capital Damascus.

The bombardment has forced many people into hiding in underground shelters with little food and medical supplies as a government siege continues.

Other activists also claim government forces used phosphorous bombs in their latest attacks.

The Britain-based Syrian Observatory for Human Rights said that 510 civilians have now died in the week-long bombardment.

The White Helmets said it has documented the names of 420 people who have been killed since Sunday, adding that dozens more have still not been identified.

Proposals for a fresh ceasefire which were circulated on Friday were held up after Russia labelled the prospect of a halt to the fighting unrealistic.

A text of the resolution demanded "that all parties cease hostilities without delay".

It said a cease-fire must be followed immediately by access for humanitarian convoys and medical teams to evacuate the critically ill and wounded.

But reservations from Russia, which has been the main backer of Syrian president Bashar Assad since the conflict began seven years ago, have hindered its implementation.