At least 34 civilians were killed on Tuesday in suspected Russian air strikes on two markets in northern Syria, a monitoring group said.
The raids killed 16 civilians at a market for fuel in Idlib province, the Syrian Observatory for Human Rights said.
Another 18 civilians, including four women, were killed after strikes on a market in a village held by the Islamic State jihadist group (ISIS) in the northern Aleppo province.
The Britain-based Observatory said both tolls were likely to rise as many people were critically wounded.