Syrian rebels say fight for Aleppo has begun

This citizen journalist image shot through a broken car window shows smoke billowing from a building after fighting between rebels and Syrian troops in the Yarmouk camp for Palestinian refugees in south Damascus, Syria, Saturday, July 21, 2012. This week, fierce fighting between troops and rebels reached the Syrian capital, the central bastion of Bashar Assad's rule, shattering parts of the city and sending thousands of people fleeing to neighboring Lebanon and Iraq. Activists and residents reported a tense calm in Damascus Saturday but said sporadic gunfire and explosions could be heard throughout the night. (AP Photo)Syrian rebels have launched an offensive to "liberate" the country's largest city of Aleppo, an opposition commander said Sunday, while in Damascus government troops backed by helicopter gunships wrested back control of rebel-held neighborhoods.