The Britain-based Syrian Observatory for Human Rights said 19 civilians were among the dead in today's attack on the town of al-Bab, including three children and three women.
Scores of others were wounded in the attack which saw army helicopters drop explosives-filled barrels on the town in the northern province of Aleppo.
The Local Coordination Committees group said 29 people were killed.
Al-Bab is held by the Islamic State group and is a frequent target of Syrian army strikes that often kill civilians.
