Air strikes hit parts of the Idlib region in northwest Syria, the country's last major opposition 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 UK-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.
The Civil Defence, an emergency service that operates in opposition territory, said air strikes damaged its centre in the village of al-Tamanaa in Idlib.
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.
