Russian jets hit rebel training camps in northwestern Syria near the Turkish border on Sunday, as Syrian artillery killed seven civilians and injured 14 medics in an attack on a hospital in the area, witnesses and rebel sources said.
The sources said a Russian surface-to-surface missile also hit the town of Qah while Russian air strikes came close to densely populated refugee camps along the border with Turkey.
A gas facility was hit near Sarmada city in Idlib province, but there were no immediate reports of casualties.
The spokesman for the National Army, a Turkish-backed rebel alliance in the northwest, said Russia, which backs the government in Damascus, sought to destabilize the last rebel stronghold in Syria but the strikes did not signal an imminent major assault against Idlib.
"The Russian aerial strikes are continuing. Ballistic missiles have also hit areas close to civilian centers." Major Youssef Hamoud told Reuters. "They seek to sow chaos and confusion," he added.
Turkey's Defence Ministry said a missile launched by Syrian government forces had struck Qah and a truck and trailer park near Sarmada, injuring seven civilians.
It said a statement had been sent to Russia asking for the attacks to stop immediately and Turkish troops had been alerted.
There was no immediate comment from Moscow.
A woman and a child were among the seven civilians killed when mortar rounds hit the hospital in the city of Atareb.
The Turkish Defence Ministry said earlier that five people were killed and 10 injured in an artillery attack by Damascus-backed forces on the hospital, which is located in an area of northwest Syria where Turkey has a military presence.
Videos received by Reuters from two witnesses showed a ward damaged and civil defense rescuers carrying bloodstained patients outside. Reuters could not verify their authenticity.
Fighting between Syrian army forces and rebels has subsided since a deal a year ago ended a Russian-led bombing campaign that had displaced over a million people in the region which borders Turkey after months of fighting that killed several thousand civilians.
Residents say although there have been no major hostilities, the calm is occasionally ruptured by Russian strikes on rebel outposts and by Iranian and Syrian-backed militias shelling towns and cities in the enclave where nearly four million civilians live.
Syria and Russia say they only target militant Islamists and deny any indiscriminate shelling of civilian areas.