BAGHDAD &

Iraqi security forces and Shiite militiamen clashed today in Baghdad's Sadr City neighborhood, where attacks killed 16 people on the fifth anniversary of the U.S. capture of the capital.




The heavily fortified Green Zone, which houses diplomatic missions and much of Iraq's government, came under renewed attack by rockets or mortars despite a daylong vehicle ban apparently aimed at preventing Shiite gunmen from moving freely about the city.




The U.S. embassy said there were no immediate reports of casualties in the Green Zone attack.




The euphoria of victory dissipated soon after U.S. troops swept into Baghdad and toppled Saddam Hussein's regime, with the outbreak of a Sunni insurgency, then Sunni-Shiite slaughter and now battles against Shiite militiamen.




As the number of U.S. forces in Iraq has gradually come down in the past three months, car bombings, suicide attacks, civilian casualties and ethno-sectarian violence have risen.




In testimony to a congressional committee Tuesday, U.S. commander Gen. David Petraeus called for an open-ended suspension of U.S. troop withdrawals this summer because of concern over the renewed fighting.




Police said the seven of the victims in Sadr City &

including three children &

died when projectiles slammed into a house in the sprawling slum, a stronghold of the Mahdi Army militia of anti-American cleric Muqtada al-Sadr.




Twenty-seven people were wounded, said a hospital official who asked not to be identified because he was not authorized to speak to the media. Police said the blasts were caused by mortar rounds.




A mortar shell crashed into a nearby residential area in the district, killing seven people and wounding 36 others, police and hospital officials said.




The U.S. military said one of its drones launched a Hellfire missile during the night at two gunmen shooting at government forces in a different part of Sadr City.




The military also announced that U.S. special forces uncovered a large weapons cache last week in the Jazeera Desert in northwestern Iraq. The arms, located in an abandoned Iraqi air force radar station, included shoulder-launched SA-7 surface-to-air missiles, rockets, heavy machine guns, mortars, ammunition and hand grenades.




The Iraqi military ordered vehicles and motorcycles off the streets from 5 a.m. today until midnight despite a decision by al-Sadr to call off his "million-strong" demonstration against the American military presence.




The military said today that an American soldier had died from non-combat related injuries. At least 12 American service members have died in Iraq since Sunday, and the shelling of the Green Zone has become almost a daily occurrence.




A Sunni Arab clerical group, meanwhile, claimed today that tribesmen who broke with al-Qaida and now work with the Americans have assassinated at least six freed prisoners in Haditha, a town in Anbar Province.




"We are witnessing the killing of several people released from the occupation detention centers by men belonging to the awakening projects," the Association of Muslim Scholars said, referring to the "awakening councils" that have been a key element of the U.S. strategy to pacify Sunni areas.




Residents contacted by telephone said some awakening council members were taking revenge on former detainees who had killed their relatives when the area was under the control of al-Qaida. They spoke on condition of anonymity out of fear for their own safety.




Haditha police confirmed the recent killings but gave no details.