Syrian army helicopters bombarded the northern rebel-held town of Al-Bab for a second day on Sunday (December 1), killing 20 people including four women when they dropped improvised barrel bombs on a market district, a monitoring group said.
The Syrian Observatory for Human Rights said the death toll could rise because many people were severely wounded in the raid.
The bombardment of Al-Bab, around 40 km 25 miles north-east of the divided city of Aleppo, follows gains by Assad's forces on Aleppo's south-east approaches last month and could herald a similar ground offensive in the area.
It comes at a time of heavy fighting across the country, particularly around Aleppo, in the Qalamoun region which overlooks the main highway north from Damascus, and the eastern suburbs of the capital.
More than 100,000 people have been killed in the Syrian 2-1/2 year conflict, which has split the Middle East.
There is little sign that diplomacy will end the conflict and the fighting has, if anything, escalated since the United Nations announced on Monday that a long-delayed peace conference would be held in Geneva on Jan. 22.