Syria’s northwestern corner, including the Idlib region, is the last major chunk of territory still in rebel hands after more than eight years of war.
The air strikes hit a fruit and vegetable market in Maaret al-Numan, south of Idlib, and a second produce market in Saraqib to the east, according to the White Helmets, a civil defense and rescue group operating in rebel areas of Syria.
Photos and videos posted by the group on Twitter showed victims being carried away from demolished produce stands and charred vehicles.
Syrian President Bashar al-Assad met an envoy to Russian President Vladimir Putin on Monday to discuss the situation in Idlib and attacks launched by militant groups based there, according to a tweet from Syria’s presidency.
There was no mention of the air strikes on Syrian state media. The British-based Syrian Observatory for Human Rights, a war monitor, put the number of those killed in the attack at 15. It said separately that Russian air strikes had targeted a prison in Idlib, causing casualties and prisoners to flee.
It did not provide specific figures.
Russia, which has supported Assad against rebels and militants in his country’s civil war, and Turkey, long a backer of rebels, co-sponsored a “de-escalation” of conflict agreement for the area earlier this year that has since faltered.
The region is home to hundreds of thousands of people who fled other parts of Syria as government forces advanced through the country since Moscow joined the war on the side of Assad in 2015, tipping the conflict in his favor.