Photo Gallery: Riots in Pakistan: Sept. 21, 2012 4/20

A Pakistani police officer fires in the air during clashes that erupted as demonstrators tried to approach the U.S. embassy in Islamabad, Pakistan, Friday, Sept. 21, 2012. Protests by tens of thousands of Pakistanis infuriated by an anti-Islam film descended into deadly violence on Friday, with police firing tear gas and live ammunition in an attempt to subdue rioters who hurled rocks and set fire to buildings in some cities.  Four people were killed and dozens injured on a day the government declared a holiday to allow people to rally against the video. AP photo