Armed groups killed entire families, including women and children, during an outbreak of sectarian violence in Syria last week, the United Nations human rights office said on Tuesday.

The killings occurred in the heartland of Syria’s Alawite minority, escalating after a nascent insurgency formed against the Sunni Islamist government.

Entire families including women and children were killed in Syria's coastal region as part of a series of sectarian killings by the army against an insurgency by Bashar al-Assad loyalists, the U.N human rights office said on Tuesday.

A Syrian military operation against remnants of the former Assad regime has now ended, having sparked some of the worst violence seen in the country in years.