Rebels launch fierce assault in Syria's divided Aleppo

Rebel fighters launched a major assault on government-held districts of Syria's long-divided Aleppo on Monday, after the regime severed their only remaining supply route into the battleground city.

Once Syria's economic powerhouse, Aleppo has been ravaged by the war that began with anti-government protests in 2011 and which has since killed more than 280 000 people.

Rebels launched the offensive at dawn to reopen the Castello Road, their last lifeline into the northern city, an AFP correspondent said.

The Britain-based Syrian Observatory for Human Rights said 19 regime forces were killed on Monday when rebels blew up a tunnel in the Old City.