U.S. forces battled insurgents loyal to Shiite cleric Muqtada al-Sadr in the Baghdad slum of Sadr City on Tuesday, the U.S. military said. At least 33 people were killed and 193 injured in the fighting, Iraqi authorities said. U.S. Army Capt. Brian O'Malley said several American soldiers have been injured. The fighting erupted when insurgents attacked U.S. forces carrying out routine patrols, O'Malley said. "We just kept coming under fire," he said. Residents said loud explosions and gunfire could be heard across Sadr City on Monday night and that clashes spilled over into Tuesday morning. A senior Health Ministry official, said a total of 33 people have been killed and 193 injured in the Sadr City clashes in the past 24 hours.