Mahmoud Alloush, a pro-opposition civil defense official based in Aleppo, said that warplanes had targeted residential neighborhoods and that casualties included several women and children.

The strikes damaged a number of buildings and vehicles in the area, Alloush said, adding that firefighters and civil defense teams were still trying to extinguish fires caused by the strikes.

Since Sept. 19, when the Syrian regime announced the end of a week-long truce sponsored by Washington and Moscow, regime and Russian warplanes have pounded opposition-held parts of Aleppo.

Hundreds of local civilians have reportedly been killed or injured in the attacks, which remain ongoing.

Syria has been locked in a vicious civil war since early 2011, when the Assad regime cracked down on pro-democracy protests -- which erupted as part of the "Arab Spring" uprisings -- with unexpected ferocity.

The Syrian Center for Policy Research, a Beirut-based NGO, has put the total death toll from the five-year conflict at more than 470,000.