The first anniversary of the start of the war that ousted Saddam Hussein (searchwas a day like many others in Iraq: a mortar attack in a northern city, an attempt to kill a politician and news of a U.S. Marine cut down by rebel fire.

Overall, Saturday was average by recent Iraqi standards.

The millions of Iraqis who exulted in Saddam's downfall did not publicly celebrate the day, nor were there street protests from those who enjoyed his patronage — partly because public gatherings are vulnerable to homicide attackers (search), car bombs, shootings and other violence.

Even those who opposed Saddam are uncomfortable with the invasion and extended occupation of Iraq by foreign armies.

Many Iraqis fear daily they will be caught in the crossfire of the conflict between U.S. forces and anti-American insurgents and other shadowy assailants, and said they felt more insecure now than they did before the United States launched military strikes.

On Sunday, two mortar rounds landed in the headquarters of the U.S.-led coalition, an American official said, while a third round landed on a street outside the compound. The U.S. official, who spoke on condition of anonymity, said it was not clear if anybody was killed or wounded.

Another U.S. military official said staff at the headquarters were instructed to move to bunkers following the blasts. People in the neighborhood outside the compound earlier said an explosion damaged some cars but caused no casualties.

Hours after U.S. Marines officially took control Saturday from the 82nd Airborne Division of a swath of territory west of Baghdad, the U.S. military said rebels had killed a U.S. Marine in the area, Anbar province, a day earlier. Two Marines also died in combat Wednesday in Anbar, which includes parts of the so-called Sunni Triangle (searchwhere guerrilla attacks have been fierce.

A rocket attack Saturday evening near the restive city of Fallujah killed two U.S. soldiers and wounded six, a U.S. military official said.

At the handover ceremony at a U.S. base in Ramadi, Marine commander Maj. Gen. James Mattis issued a warning to insurgents.

"We expect to be the best friends to Iraqis who are trying to put their country back together. And for those who want to fight, for the foreign fighters and former regime people, they'll regret it. We're going to handle them very roughly," he said.

Also Saturday, the U.S. Army said a 1st Infantry Division soldier was fatally electrocuted while working on communication equipment at a military base in Baqouba, north of Baghdad. And near Taji, also north of the capital, one soldier died and two were wounded after their vehicle rolled over Thursday, the military said.

The three deaths on Saturday would raise to 573 U.S. service members who have died since the beginning of military operations in Iraq on March 20, according to the most recent Department of Defense figures. Of those 391 died as a result of hostile action, and 183 died of non-hostile causes.

In other violence:

—A U.S. military helicopter was shot down Friday by rebels near the town of Amariya, west of Baghdad. The two crewmen escaped injury and the helicopter was recovered, said Brig. Gen. Mark Kimmitt, deputy director of U.S. military operations.

—Insurgents fired four mortar rounds at the offices of a Kurdish political party in the northern city of Mosul on Saturday but missed and killed a driver on a nearby street, Iraqi police said. Guards fired at the rebels; three party members and a passer-by were wounded in the shootout.

—In the northern city of Kirkuk, Iraqi police said Subhi Saber a Turkman politician, survived an assassination attempt Saturday. Assailants opened fire on Saber's car, injuring his driver, but the politician escaped.

—The U.S. military said it charged six U.S. military police officers Saturday over the alleged abuse in November and December of about 20 Iraqi detainees at Abu Ghraib prison on the outskirts of Baghdad.

President Bush marked the anniversary of the beginning of the war in a speech Friday at the White House, declaring that the fall of Saddam removed a source of violence, aggression and instability in the Middle East.

But some Baghdad residents said Iraqis were less safe.

"The security situation is worse than one year ago. I cannot take my family outside at nights. When I walk in the street, I do not know when a bomb is going to explode and kill me," said Ammar Samir, 26, who works for a private trading company. "The Americans have failed to provide security and prosperity to the Iraqi people."

Bush made his decision to go to war despite widespread international opposition.

Thousands of war protesters marched in Asian, American and European cities on the first anniversary of the invasion, demanding the withdrawal of U.S.-led troops from Iraq.

The top administrator in Iraq, L. Paul Bremer, marked the anniversary by noting the ways the coalition had improved the lives of Iraqis over the past year: the electricity supply was back to prewar levels and climbing, unemployment was down and per capita income had risen by 33 percent this year.

He said the coalition had completed thousands of projects such as generator installations and school refurbishment but admitted that attacks were interfering with big, capital-intensive projects because firms have to spend more on security.

The political process has advanced, with the U.S.-appointed Governing Council signing an interim constitution ahead of the handover of power to Iraqis on June 30. But many details of Iraq's political transition have yet to be mapped out, and there are fears that sectarian divisions could disrupt the process.