Fight rages in Aleppo, where Arab League chief says war crimes being committed

Northern Syria (CNN) -- Syrian troops at a besieged military base just north of Aleppo fired out in three directions on Sunday in the face of a rebel onslaught, part of a high-stakes battle for a city where a top regional leader claimed war crimes are being committed. For days, anti-government forces have been trying to take over the northern Syrian city, where many residents appear to support their cause, only to be answered by fierce fighting by the Syrian military. The fight for the military base is one of many hotspots of violence raging around Aleppo, which is the commercial and cultural center of the Middle Eastern nation and its largest city. CNN's Ivan Watson inside Syria Yet it is indicative, in many ways, of what's going on, with the rebels attacking from seemingly many different directions and scores of troops inside firing back furiously with machine guns -- oftentimes straight into neighboring villages. Rockets and shells routinely land in residential communities, many of which are largely deserted as civilians flee the area. On Sunday, families continued to use motorcycles, cars and whatever other means to escape the city. They are among the roughly 200,000 people in Aleppo and surrounding areas to flee shelling and heavy weapon fire over the past two days, according to Valerie Amos, the U.N.'s under-secretary-general for humanitarian affairs.