At least 84 civilians, mainly women and children, have been killed in three days of militant shelling of Syria’s Aleppo city. Syrian officials say nearly 300 people also wounded as a result of the militant attacks targeting residential areas in the government-held parts of the embattled city. The latest deaths come amid reports that terrorists used poisonous gas during attacks against civilians on Sunday. According to a senior UN official in Syria, a tank shell also hit a UN building in western Aleppo. Amnesty International has slammed the assaults saying armed groups violated international humanitarian law by bombarding civilian neighborhoods. Fighting has intensified in Aleppo with hundreds of terrorists massing around the western edge of the flashpoint city. The Syrian army has so far managed to foil attempts by the terrorists to break the siege of the eastern part of Aleppo where they are holed up.