Aleppo (Syria) (AFP) - Syria's government is launching a major assault in the northern province of Aleppo, seeking in part to cut off rebel access to Aleppo city, a security source told AFP.

"Through its operations, the army is trying to broaden its security zone around the city," and prevent the rebels from receiving supplies and reinforcements from the suburbs, the source said.

Once Syria's commercial hub, Aleppo city is now divided between government control in the west and rebel control in the east.

The broader province is split as well, with the Islamic State jihadist group present in parts of the east, along with the regime, and rebel groups and Syria's Al-Qaeda affiliate, Al-Nusra Front, in the west.

But with backing from Russian air strikes and foreign fighters, Syria's armed forces are slowly advancing south and southeast of the city.

One commander with pro-government forces said they were currently fighting on seven fronts across Aleppo province, and the operation was expected to expand further.

"This will be the biggest military operation in Syria since the beginning of the war," he told AFP.