The Syrian Observatory for Human Rights said at least 17 people were killed in the last 24 hours by Syrian regime shelling in the northwest.
Shelling by Syrian regime forces of rebel-held areas in the northwest of the country has killed 17 civilians in the past 24 hours, a war monitoring group said on Thursday.
The Syrian Observatory for Human Rights group said the shelling was in different locations and that more than half the dead were under the age of 18.
Violence has escalated in northwestern Syria this year along the frontline between pro-regime forces and the largest remaining territory held by Syrian rebel groups.
The area is subject to a ceasefire agreement struck in September between Russia and Turkey to avert a major regime offensive to retake the northwest. Moscow is the regime's strongest ally and Turkey backs some rebel groups.
The northwest, including Idlib province and parts of Hama and Aleppo provinces, is home to about three million people, half of whom have already been internally displaced, the United Nations says.
Early this year, the Hayat Tahrir Sham (HTS), a former Al Qaeda affiliate group in the northwest seized most of the enclave from other rebel factions.
Turkish-backed rebels hold an adjacent enclave in northern Aleppo province where there is no active fighting with the regime.