Five civilians were injured in a regime airstrike in Syria's northwestern Idlib province, according to the White Helmets civil defence agency on Sunday, Anadolu Agency reported.
The overnight attack targeted the towns of Urum al-Jawz and Bsanqul and Jabal al-Arabaeen, which overlooks the town of Ariha, it said.
White Helmets said three children were among those injured in the attack.
In September, Turkey and Russia agreed to turn Idlib into a de-escalation zone in which acts of aggression would be strictly prohibited.
Syria has only just begun to emerge from a devastating conflict that began in 2011, when the Bashar al-Assad regime cracked down on demonstrators with unexpected severity.