Smoke rises from the site of a bomb attack in central Baghdad December 22, 2011. A series of explosions hit Baghdad on Thursday, killing at least seven people in the first wave of attacks on Iraq's capital since a crisis erupted between its Shi'ite-led government and Sunni rivals after the last U.S. troops left, police said. REUTERS/Mohammed Ameen (IRAQ - Tags: CIVIL UNREST TPX IMAGES OF THE DAY)