An Iraqi soldier-in-training smuggled real bullets into a training exercise on Saturday and opened fire, killing two American troops. The Iraqi trainee was immediately killed by other American soldiers. A military official said the exercise was not meant to involve live ammunition, and that the attack had clearly been planned. The U.S. troops involved were from the 4th Brigade, 1st Cavalry Division, based at Fort Hood, Texas. The shooting came just hours after a U.S. Marine killed an Afghan trainee who turned hostile during a security operation. Both attacks re-ignited debates about the stability of training operations in the two occupied Middle Eastern nations, and the tensions between Iraqi and Afghan soldiers and the coalition forces training them.