The Syrian Observatory for Human Rights war monitor has reported that 745 Alawite civilians were killed in Latakia and Tartus provinces.
The Britain-based Observatory said they were killed in "executions" carried out by security personnel or pro-government fighters, accompanied by the "looting of homes and properties".
The fighting has also killed 125 members of the security forces and 148 pro-Assad fighters, according to the Observatory, taking the overall death toll to 1,018.
The official SANA news agency reported on Saturday that security forces had deployed to Latakia, as well as Jableh and Baniyas further south, to restore order.
Baniyas resident Samir Haidar, 67, told AFP two of his brothers and his niece were killed by "armed groups" that entered people's homes, adding that there were "foreigners among them".