A Syrian rebel flashes a victory sign as he drives past a graffiti which reads: " Allah Akbar" (or God is great ) in Attarib, on the outskirts of Aleppo province.

Syrian helicopter gunships and artillery pounded two key areas of Aleppo on Tuesday, extending the army's campaign to control the country's biggest city, but rebel fighters said troops loyal to President Bashar al-Assad had been forced to retreat.

Heavy gunfire sounded from the Salaheddine district in the south-west of the city, where rebels denied they had been driven out by the army.