Syrian activists say government forces are pounding a rebel stronghold in the mountainous region near the Lebanese border in which a group of nuns are believed to have been held by opposition fighters.
The Britain-based Syrian Observatory for Human Rights says president Bashar Assad's forces launched several air strikes on Yabroud on Tuesday. They also shelled the town, in the Qalamoun area, with heavy artillery.
Twelve nuns are believed to have been in Yabroud after they were taken by opposition fighters eight days ago from a nearby Greek Orthodox convent.
The army launched a crushing offensive in Qalamoun last month to cut off rebels' supply routes from Lebanon and open the main north-south highway that links Damascus with Assad's strongholds on the coast.