Three soldiers were killed today when a grenade was thrown at them as they guarded a hospital north of Baghdad, US military officials and residents said.
A military spokesman said four soldiers from the 4th Infantry Division were wounded in the attack in Baquba, 50 km (30 miles) north of Baghdad, in the "Sunni triangle" where American troops have come under frequent attack.
The attack brings to more than 80 the number of US soldiers killed at enemy hands since Washington declared an end to major combat in Iraq on May 1st. Eight have died since US forces killed Saddam Hussein's sons Uday and Qusay on Tuesday.
Residents said an attacker had thrown the grenade from the roof of the hospital, a modest one-storey building on the banks of a tributary of the Tigris river. US troops sealed off the building after the attack and barred people from leaving.
Dozens of worried Iraqis with relatives in the hospital gathered outside the hospital gates.
"My wife and my baby boy are inside. I have a one-year-old daughter at home who needs her mother. We want the Americans to let them out," said one man, Mohammed Abdul Sattar.
Soldiers said nobody would be allowed in or out of the hospital until tomorrow. Everybody inside the building was being photographed as part of the investigation into the attack.
Soldiers have been guarding hospitals and other public buildings to try to stem the lawlessness and looting following the toppling of Saddam.
US officials blame die-hard supporters of Saddam for the wave of ambushes on American troops, mainly in Baghdad and the Sunni Muslim heartland to the north and west.
Arab television networks have broadcast pictures of masked men with rocket-propelled grenades and automatic rifles vowing to avenge the deaths of Uday and Qusay, killed when US troops stormed their hideout in northern Iraq.