Activists say at least nine people were killed, including three children, in a Syrian government airstrike that targeted a rebel-held town near the capital Damascus.

The Britain-based Syrian Observatory for Human Rights said there were likely more dead in Friday's airstrike, because people were buried under the rubble in the town of Saqba.

Local activists on a Saqba Facebook group said the strike hit a residential building and published a series of videos showing the strike's aftermath. The videos appeared genuine and corresponded to The Associated Press reporting of the event.

Government forces have been pounding areas near Saqba for months as they try to repel rebels fighting to overthrow the rule of President Bashar Assad.

Syrian airstrikes have killed thousands of civilians in the grinding war, now deep into its fourth year.