Syrian government forces carried out at least eight chemical attacks during the final weeks of the battle for Aleppo , killing nine people including four children, Human Rights Watch said Monday, according to AFP . The group said it interviewed witnesses, collected photos and reviewed video footage indicating that chlorine bombs were dropped from government helicopters during the offensive from November 17 to December 13. Around 200 people were injured by the toxic gases used on opposition-controlled areas of the northern city, it said.