Syrian forces have killed at least 23 people in a suburb of the capital Damascus, anti-regime activists say.
The Britain-based Syrian Observatory for Human Rights said 18 civilians were killed in an airstrike on the city of Duma, north east of Damascus.
Five other rebel fighters were killed in clashes with regime forces nearby.
Syrian forces have stepped up their use of airpower against rebels seeking to topple President Bashar Assad as opposition fighters have made gains on the ground.
Activists say more than 35,000 people have been killed since Syria's troubles began in March, 2011.