Syrian regime forces dumped barrel bombs on a rebel-held area of Aleppo killing 10 civilians, including a family of four, a monitoring group said.
An AFP correspondent who later toured the area said the raids also caused heavy destruction in Bab al-Nairab neighbourhood in the old district of Aleppo, Syria's second city.
The Syrian Observatory for Human Rights said five barrel bombs were dropped on the district killing 10 civilians, including a man, his wife and their two children, as well as three other children and a woman.
The raids inflicted heavy damage to buildings in Bab al-Nairab where volunteers were sifting through mounds of blood-stained debris to search for survivors, said the AFP correspondent.
"We are hearing voices but we cannot locate them because of the destruction," a rescuer said, as the body of a man and a teenager were pulled out of the debris.
On Saturday, residents and the Observatory reported that 16 people were killed when a regime helicopter dropped a barrel bomb on another rebel-held area of Aleppo.
Residents said they had found children "torn apart" from the force of the attack.
The regime has pressed on with its barrel bomb campaign despite a United Nations resolution on February 22 banning their indiscriminate use in populated areas.
HRW described barrel bombs as "cheaply made, locally produced, and typically constructed from large oil drums, gas cylinders, and water tanks, filled with high explosives and scrap metal to enhance fragmentation, and then dropped from helicopters".