A car bomb exploded in a jammed commercial district Thursday, turning the sky gray as shops and restaurants caught fire in the most deadly of a string of attacks that killed 21, including a general and colonel who were assassinated. Iraqis expressed growing fury at the relentless bloodshed, throwing stones at police and U.S. forces who came to the scene of the bombing. More than 90 were also wounded in Thursday's violence. On Friday, a roadside bomb hit a U.S. military convoy on a highway to Baghdad. No casualties were immediately reported, but Associated Press Television News footage from the scene showed a Humvee, its hood open, consumed in flames.