Syrian activists say that government airstrikes on a rebel-held town have killed at least 16 people.

Local activist Hassan Taqulden and the Britain-based Syrian Observatory for Human Rights said Saturday that at least five air raids targeted buildings in the city of Douma. They said the bombings occurred Friday evening.

Taqulden said most of those killed were civilians. The Observatory said at least three children and one woman were killed. Both said the death toll was likely to rise because people were still buried under rubble.

Syria's military stepped up its shelling of Douma during the summer as part of its intensified battle to wrest back rebel-held towns around the capital, Damascus.

Activists say Syria's three-year civil war has killed more than 200,000 people.