BAGHDAD, Iraq -- U.S. forces in western Iraq are facing fierce resistance to their new effort to take control of the Syrian border, with car bombs and an apparent ambush killing eight U.S. troops in a single day, Army and Marine officials said yesterday.

Tony Dejak, Associated Press Lt. Col. Kevin Rush of the Headquarters and Service Co. 3rd Battalion, 25th Marines answers questions from reporters yesterday in Brook Park, Ohio. Click photo for larger image.

The deadly series of attacks Monday included the ambush of six Marines on patrol outside of Haditha, Marine officials said. Five of the Marines were killed by small-arms fire in the initial assault, but one was "unaccounted for" and later found dead a couple miles away, a Marine statement said. Officials declined to say whether he was taken hostage before he was killed. The military was investigating the incident.

The six Marines killed were conducting "dismounted" operations, meaning they were out of their armored vehicles, when insurgents fired on the men, the statement said. While bombs in Iraq have occasionally killed a handful of Marines in a single attack, it is unusual for five to die from small-arms fire. Marines outside their armored vehicles generally wear body armor and carry weapons at all times, except when sleeping.

U.S. military statements gave no other details, saying the attack was under investigation.

In Brook Park, Ohio, Lance Cpl. Jeff Boskovitch was remembered as an aspiring police officer who planned to set a wedding date with his girlfriend when he returned home from Iraq this fall.

Boskovitch family photo via AP Jeff Boskovitch in Iraq. Click photo for larger image.

But first he had a job to do in Iraq, where he believed the U.S. military was making a difference, his uncle said yesterday.

Boskovitch, 25, of North Royalton, was among six Marine reservists attached to the same suburban Cleveland unit who were killed Monday in an attack west of Baghdad.

"We got a lot of e-mail from him," said Paul Boskovitch, who said his nephew joined the Marine reserves in 2000. "He felt he was making a difference there and that the Iraqi people were appreciative of what they were doing. He loved the Marines and he loved his unit."

All six reservists were from northeastern Ohio, and were members of the Headquarters and Service Co. 3rd Battalion, 25th Marines, based in Brook Park, a suburb of about 21,000 people southwest of Cleveland.

Unit members in Iraq were under a military-imposed communications blackout to make sure none of the names were disclosed until victims' families were notified. Family members identified three of the dead as Boskovitch, Lance Cpl. Brian Montgomery of Willoughby and Sgt. Nathaniel Rock of Toronto.

Montgomery, 26, joined the Marine reserves in June 2002, his father said. "I've never seen a man who was more patriotic than him," Paul Montgomery said as he choked back tears.

Montgomery's 21-year-old brother, Eric, is serving in the same company and will be coming home for the funeral, the father said.

Rock, 26, spent six years in the Marines after graduating from high school in 1997 and then joined the reserves, said his mother, Adriana Rock. At home in Ohio, he worked as a part-time police officer in Martins Ferry.

"He was very proud to be a Marine," she said.

The battalion was activated in January and went to Iraq in March.

"It's difficult and our thoughts and prayers go out to their families," Mayor Mark Elliott said.

In addition to the Ohioans, a seventh Marine was killed by a car bomb in nearby Hit. All of the slain Marines were assigned to the 2nd Marine Division's Regimental Combat Team 2.

A U.S. Army soldier was killed near the Syrian border in a car bombing that also injured an Army Times reporter.

The eight deaths Monday bring to more than 1,800 the number of U.S. troops killed since the start of the March 2003 invasion. In an Internet statement, the Army of Ansar al Sunna insurgent group claimed responsibility for killing the Marines, Reuters reported.

There was no word from the military on whether any insurgents were killed in the incidents in western Iraq. The deaths of the Americans, though, highlight the intensity of the fighting in the area following a recent order by Army Gen. George W. Casey, the top U.S. commander in the country, to control Iraq's western border by November.

Separately, the interim government of Iraq, claimant to the world's second-largest oil reserves, announced fuel rationing during a summer of miles-long gas lines. Reasons for the rationing cited by government officials and analysts matched a litany of Iraq's problems: insurgent attacks, corruption, decayed infrastructure and mismanagement.

Army troops with the 1st Brigade of the 25th Infantry Division two weeks ago began setting up the first long-term U.S. outpost in the northern Euphrates River valley, in the small city of Rawah, and are seeking to wrest control of a historic smuggling route. Military officials say intelligence reports suggest that insurgents have been using the route to ferry in as many as 200 foreign fighters each month from Syria, along with bomb-laden cars and trucks, east toward Baghdad and other city centers.

U.S. military officials generally agree that foreign fighters make up fewer than 10 percent of the insurgency but play a prominent role in coordinating and directing major attacks. A majority of the insurgents, U.S. authorities say, are Sunni Arabs from Iraq.

As the military pressed on with its campaign in western Iraq, families in the impoverished Baghdad neighborhood of Abu Disheer mourned the deaths of 22 Shiite Muslim men who were executed and left Monday in a trash heap in the nearby Um Maalif area.

What made the incident unusual was that none of the men appeared to have a connection with the government or security forces, except for two former policemen. Insurgents often target Iraqi security forces.