Syria's state media says at least 12 civilians have been killed, including eight from one family, when shells fired by rebel fighters landed in government-held districts of the northern city of Aleppo.

Syrian state TV said the shelling Saturday also left 45 injured. The dead included children, the TV report said without elaborating.

Aleppo, Syria's former commercial hub, became a key front in the country's civil war after rebels launched an offensive there in July 2012. It is divided between rebel and government controlled districts.

Syrian rebels have shelled residential areas in government-held parts of the contested city in the past, killing hundreds of people. Government warplanes have dropped explosives-filled barrels on rebel-held neighborhoods in Aleppo and other cities, killing thousands.