BAGHDAD - U.S. forces have killed 14 militants in the Baghdad slum of Sadr City, a stronghold of gunmen loyal to anti-American Shi'ite cleric Moqtada al-Sadr, the military said on Friday.The gunmen were killed in several clashes on Thursday, the military said in a statement. It said air strikes and tanks were used to attack militiamen attempting to launch rockets from the slum or shoot at U.S. troops on patrol. Hospitals in Sadr City said they had received four bodies and 51 wounded. Among the wounded were children.