At least 40 were killed, 70 injured in a Russian air attack on a busy marketplace in Syria's Idlib province on Sunday morning, Anadolu Agency reported.
The attack occurred in the town of Ariha, 15km south of Idlib city, a monitoring group reportedly said.
Rami Abdulrahman, director of the Observatory, said a total of at least 60 people had been killed and wounded in the attack. The pro-opposition Orient TV reported an initial death toll of 40.
Officials at the Russian defense ministry could not immediately be reached for comment. The Russian air force has been conducting air strikes in support of Bashar al-Assad since Sept. 30. It says it targets the Daesh and other "terrorists", but critics accuse it of targeting moderate opposition fighters as well as civilians.