Al-Jazeera Video: Rebel bastions in Aleppo targeted

"The Syrian government is reported to be sending masses of troops to the northern city of Aleppo.

Aleppo is home to 2.5 million people and the fate of Salaheddin district, seen as a gateway for the army, could determine the outcome of the conflict that has already claimed some 18,000 lives.

Al Jazeera's Nicole Johnston reports."