The battles to control the city took place from 2012 to 2016. Aleppo, located in north-western Syria, is the largest city in this country. About 2.5 million people had lived there before the war. In July 2012 anti-government militias occupied three districts of Aleppo. Since then, more and more fierce clashes took place there. After more than four years, in December 2016, regime forces supported by Iran and Russia broke the siege. According to the data of the Syrian Observatory For Human Rights, 21,452 civilians were killed in the Battle of Aleppo.