At least 44 people killed, including children, and many more wounded on Sunday in a suspected Russian air strike on a crowded marketplace in Idlib province, activists have told Al Jazeera, Doha-based news broadcaster.
The strikes hit the town of Ariha, which is controlled by the Army of Conquest, a rebel alliance which includes the Nusra Front, the UK-based Syrian Observatory for Human Rights said, according to the report.
In addition to the market, several other areas of the town were hit, the group said.
Local news channel reported cluster bombs were used in the raid by a Russian fighter jet.
As reported earlier, the Russian air force has conducted air strikes in support of President Bashar al-Assad since September 30.
Moscow says it targets the Islamic State and other "terrorists," but critics accuse it of targeting other rebel groups more than ISIS.