Syria has suffered its worst bloodshed since Bashar al-Assad was toppled from power, with more than 1,000 people reported killed in violence that has swept the coastal region since Thursday.

The death toll from two days of clashes between security forces and loyalists of ousted Syrian President Bashar al-Assad and revenge killings that followed has risen to more than 600, a war monitoring group said Saturday.

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