A U.S. soldier was killed and three were wounded Sunday in an attack outside the troubled city of Fallujah (search), where government offices were closed in a one-day strike to protest the accidental killing of eight Iraqi police and a Jordanian guard by American troops.

The center of the city was quiet and shops were open despite the strike. People went about their daily business.

During funeral ceremonies for the slain men Saturday, angry protesters fired weapons and called for violence against the American occupation to protest one of the most serious friendly fire incidents of the Iraq war.

The death of the U.S. soldier outside Fallujah brought to 155 the number of American troops to die in Iraq since President Bush declared an end to major combat on May 1. During the heavy fighting before that date, 138 soldiers died.

Secretary of State Colin Powell (search) arrived in Baghdad on Sunday for his first visit since the U.S.-led ouster of Saddam Hussein (search). Powell posed for photographs with soldiers and then boarded a helicopter for a short flight to meet various leaders.

There were no additional details about Sunday's attack, said Sgt. Amy Abbott, a U.S. military spokeswoman in Baghdad.

Massoud Ibrahim, a soft drinks vendor who saw the attack, said rocket-propelled grenades were fired at an American truck and armored vehicle. He said insurgents also fired a rocket-propelled grenade at a helicopter that arrived after the attack but missed. The helicopter was unable to land. An armored vehicle was seen being towed away.

Fallujah, 30 miles west of Baghdad, has again become an especially dangerous place for the occupying forces after the friendly fire incident near the Jordanian Hospital, just west of the city, shortly after midnight Friday.

The American military has apologized, but many in Fallujah rejected the overture and vowed to continue fighting U.S. forces.

Relations between people in Fallujah and U.S. forces have been on a knife's edge since shortly after the city was captured in April. U.S. troops came under almost daily attacks for two months after soldiers opened fire in late April on crowds of protesters in the city, killing 18 and injuring 78. The Americans said they were fired at first.

Friday's killings were certain to inflame the smoldering hatred of the American occupation.

For the rest of Iraq, the incident was likely to stoke resentment of U.S. troops — already seen by some as trigger-happy and heavy-handed.

On Saturday night in Mosul, 240 miles north of Baghdad, three soldiers were wounded in an ambush by guerrillas who bombarded them with hand grenades from the top of a building. One soldier had his leg amputated after the attack, while the other two soldiers were wounded less seriously in the legs by shrapnel.

Near Saddam's hometown of Tikrit, Iraqi security forces and U.S. Army military police swept into a desert village Sunday and arrested members of a gang accused of kidnappings, robberies and carjackings on a main road in the north.

More than 70 heavily armed, American-trained Iraqi police officers accompanied by a few dozen military police officers surrounded a tiny hamlet about 19 miles northeast of Tikrit and stormed its half-dozen mud-bricked homes.

Their targets were five members of an extended family that were sought for years for a variety of crimes but eluded arrest. After the U.S.-led invasion and collapse of Saddam's regime, similar gangs grew more active around this central Iraqi city, Tikrit police said.

"They have been carrying out carjackings, conducting illegal checkpoints, kidnapping and rapes," said Lt. Col. David Poirier, commander of the 720th MP Battalion from Fort Hood, Texas.

As attack Apache helicopters hovered overhead, the joint police team found their targets and two other wanted felons who escaped from prison in the chaos after Saddam's ouster. They discovered a number of automatic weapons, two stolen cars and a box full of money.

The raid was the second in as many weeks in the dusty villages lining the foothills of the Jabal Hambin ridge. Two weeks ago, a joint Iraqi-U.S. strike team arrested 27 people and confiscated stolen vehicles.

Many of the men involved in the raid have been trained by U.S. military police. Tikrit and its surrounding province has about 1,500 Iraqi police officers.

U.S. military forces have increasingly used Iraqi police in raids.

"People who own these houses don't feel so intimidated when it's their own people approaching," Poirier said.