The Syrian military helicopters dropped two barrel bombs on homes of civilians in Khan Al-Sheikh town in the western countryside of Damascus Saturday night.
The attack knocked down a two-story building near the cemetery of the town, killing 11 people, opposition forces said.
The victims are a 10-member family, including the father, his two wives and seven children ranging between two and seven years, and a youth.
The town has under the control of the armed opposition groups since one and a half years ago.
The attack followed clashes between the regular and opposition forces and the killing of two soldiers by opposition fighters who managed to repel a military incursion into the town.
Meanwhile, the warring parties in Syria reached a deal to preserve safety of Palestinian refugee camp in south Damascus.
The deal, signed in the presence of representatives of the local government authority, the municipal council and the UN Relief and Works Agency for Palestine Refugees (UNRWA) as well as other aid agencies, takes effect as of tomorrow Sunday.
It provides for establishing security outposts at the entrances of the camp to bar entry of militants and forming joint peace-keeping force, the Syrian Observatory for Human Rights, reported this evening.
It aims to prevent any military attacks on the camp and prepare the ground for national reconciliation and facilitate the operations of the aid agencies.
Under the deal, the state, represented by head of the Palestine division in the Syrian secret service, is the sole sponsor of the implementation of the security aspects of the deal.