More than 100 people are reported to have been killed in the Syrian village of Tremseh, in Hama province.
Opposition activists quoted residents as saying the village was attacked with helicopter gunships and tanks.
Pro-government Shabiha militia later went in on foot and carried out execution-style killings, they said.
According to the opposition Local Coordination Committees, at least 189 people were killed on Thursday in Syria, including 22 in Homs.
The Revolution Leadership Council of Hama told the Reuters news agency that most of the dead in Tremseh were civilians.
Other uncomfirmed reports suggested government troops had been trying to take back the village from opposition hands.