The Syrian government has been accused of war crimes and crimes against humanity in a new report by Amnesty International.
The human rights group says its researchers have spoken to more than 200 residents in 23 Syrian towns and villages since mid-April this year, the BBC reports.
According to the London-based group, civilians, including children, have been attacked by the security forces and militia members. It speaks of grave abuses in towns and villages around Aleppo and Idlib.
It said its information was based on more than 200 interviews in 23 Syrian towns and villages.
The vast majority of abuses were committed by government forces and their allies, Amnesty said, although it said there were incidents of rebels kidnapping and killing captured soldiers and pro-government militia.
The United Nations says at least 10,000 people have been killed since the uprising against Syrian President Bashar al-Assad began in March 2011.
Syria says it is fighting foreign-backed "terrorists" whom it blames for killing hundreds of soldiers and police.
International media cannot report freely in Syria and it is impossible to verify reports of violence.
Mountain town 'retaken'
Rebel fighters earlier pulled out of the town, al Haffa, the BBC reports.
Russia has meanwhile denied a claim by the US State Department that Moscow is sending attack helicopters to Syria.
Foreign minister Sergei Lavrov says Russia is not supplying Syria with any weapons that could be used against peaceful demonstrators.
A senior Israeli military commander says a regional proxy war is underway in Syria, with direct support on the ground for President Bashar al-Assad from his allies in Iran and the Hizbollah movement in Lebanon.
The Free Syrian Army is getting support from Sunni states Turkey, Saudi Arabia and Qatar - all allies of Washington.