Syrian government air strikes and shelling have killed at least 19 civilians in Damascus suburbs where rebels have held out through nearly seven years of the country's civil war.

The Britain-based Syrian Observatory for Human Rights said that government jets and artillery launched a wave of attacks in the Eastern Ghouta area on Sunday.

Conditions are dire inside the area, which is suffering from shortages of food and medicine due to the tightening government blockade. The UN said there are 350,000 people in need of immediate relief in Eastern Ghouta.

Earlier this month, Syrian rebels attacked a nearby military installation in the area.

The UN is due to resume peace talks between the government and the Syrian opposition in Geneva on November 28.

The opposition announced last week it was prepared to enter into direct talks with the government without pre-conditions, in a departure from earlier positions. The government has not yet named its delegation to the talks.

The UN's deputy envoy to Syria, Ramzy Ramzy, said after meeting Syrian deputy foreign minister Faisal Mekdad on Saturday in Damascus that the talks would cover four main topics - a new constitution, governance, elections and combating terrorism.