A barrage of air strikes on Saturday near a hospital in northwestern Syria killed at least 10 civilians, said the Syrian Observatory for Human Rights.
The monitor said the raids targeted the town of Milis in Idlib province, which borders Turkey and is controlled by a rebel alliance led by Al-Qaeda's former Syrian branch.
The Britain-based monitor said three children and two women were among the dead, adding that the raids were carried out by either Russian or regime warplanes.
The Idlib Media Center, which publishes news on developments in the province, said a hospital was hit in the raid by unidentified aircraft and that at least six people had been killed.
The World Health Organisation said Syria was the most dangerous place for health care workers to operate last year, with 135 attacks on health facilities and workers in 2015.
In late July, four makeshift hospitals and a local blood bank in Syria's battered Aleppo city were hit by air raids in a single day.
More than 280,000 people have been killed since Syria's conflict erupted in 2011 and millions have been forced to flee, including around five million who have sought refuge in neighbouring countries.