Syrian rebels have advanced in Aleppo, killing scores of troops loyal to President Bashar al-Assad, Al Jazeera's reporter in the northern city said.

Opposition fighters stormed the Ramouseh district in an attempt to cut the government's supply route between the city's international airport and a large army base, the reporter said on Saturday.

The latest advances came after a series of gains for the opposition in the divided city over the past few days. Rebels from the Islamic Front and the al-Qaeda-affiliated Jabhat al-Nusra have seized control of Rashidin neighbourhood and parts of Jamiat al-Zahra district where the notorious air force intelligence headquarters are located.

The regime has for several months stepped up its military campaign on Aleppo, pounding the city’s rebel-held areas with a barrage of barrel bombs and air strikes.

On Saturday, nine people, including children, died in barrel bomb shelling on two villages in Aleppo’s western suburbs, activists said.

Rebel fighters still control most of Syria’s east and north, but anti-Assad efforts in the eastern region have been undermined by infighting between different rebel groups.

At least 68 people have been reported killed in two days of clashes in Deir ez-Zor between a loose coalition of rebels, which include Jabhat al-Nusra, and the Islamic State of Iraq and the Levant (ISIL), an al-Qaeda breakaway group.

The Britain-based Syrian Observatory for Human Rights said the new wave of infighting, which erupted on Thursday, was concentrated in the village of Haseen along the Iraqi border after ISIL members were forced out of the nearby town of al-Bukamal.

Rebels have been fighting each other in Deir ez-Zor province for weeks over territory previously captured from Assad's forces, including oil fields.