According to UN human rights investigators, the Syrian government is reportedly using local militias to commit mass killings. The investigators cited accounts from witnesses and victims.

They said civilians were being harassed or arrested by militia known as Popular Committees, because they came from regions perceived as being supportive of the unrest.

The unrest in Syria erupted two years ago with Sunni rebels against President Bashar al-Assad.

According to the latest UN human rights report, both sides in the conflict have committed violations against civilians. The bodies of those killed in massacres have been burned or dumped in rivers.

The report also said rebel forces regularly execute captured Syrian soldiers and militiamen, and have established detention centres in Homs and Aleppo.