BEIRUT, Oct 28 – Syrian rebels including jihadists began a counter-attack against the army and its allies on Friday aiming to break a weeks-long siege on eastern Aleppo, insurgents said.

The assault, employing heavy shelling and suicide car bombs, was mainly focused on the city’s western edge by rebels based outside Aleppo. It included Jabhat Fateh al-Sham, a former affiliate of al Qaeda previously known as the Nusra Front, and groups fighting under the Free Syrian Army (FSA) banner.

The Syrian Observatory for Human Rights, a British-based war monitor, said more than 15 civilians had been killed and 100 wounded by rebel shelling of government-held western Aleppo. State media reported that five civilians were killed.

There were conflicting accounts of advances in areas on the city’s outskirts.

Aleppo, Syria’s biggest pre-war city,has become the main theatre of conflict between President Bashar al-Assad, backed by Iran, Russia and Shi’ite militias, and Sunni rebels including groups supported by Turkey, Gulf monarchies and the United States.

The city has been divided for years between the government-held western sector and rebel-held east, which the army and its allies put under siege this summer and where they launched a new offensive in September that medics say has killed hundreds.

Photographs showed insurgents approaching Aleppo in tanks, armoured vehicles, bulldozers, make-shift mine sweepers, pick-up trucks and on motorcycles, and showed a large column of smoke rising in the distance after an explosion.

Rebels said they had taken several positions from government forces and the Observatory said they had gained control over a checkpoint at a factory in southwest