Air strikes hit parts of the Idlib region in northwest Syria, the country's last major insurgent stronghold, a war monitoring group and a rescue service said on Thursday.
There was no immediate comment from Damascus or Moscow. Both say they target only militants.
The U.K.-based Syrian Observatory for Human Rights said warplanes, which it believed were Russian, struck the southern countryside of Idlib and a village in nearby Hama province.
>>'Israel strikes Iranian, Assad regime targets' in Syria ■ Syria, Turkey, Russia and U.S. to square off in Idlib with millions of civilians in the crosshairs | Explained ■ A massacre waiting to happen: For Syria's Idlib, diplomacy may come too late | Analysis
The Civil Defence, an emergency service that operates in rebel territory, said air strikes damaged its centre in the village of al-Tamanaa in Idlib.
- Putin, Erdogan and Rohani to Meet in Last Attempt to Avoid Bloodbath in Idlib
- French Army Chief: Ready to Strike Syria if Chemical Weapons Used
France's top military official said his forces were prepared to strike Syrian government targets if chemical weapons were used in an expected army offensive to retake Idlib.