BAGHDAD, June 18, 2005 -- U.S. troops bombarded a dusty border town with airstrikes and tank fire Friday, capturing 100 militants in the third major recent attempt to uproot tenacious insurgents who are believed to use the region to sneak foreign suicide bombers in from Syria.

Four suicide attacks around Iraq, including one in the capital, killed 11 people as rebels seeking to lead Iraq into a civil war intensified the pace and scope of attacks against Iraq's still-weak security forces. More than 60 people have died in suicide attacks over the past two days.

In a campaign codenamed Romhe, Arabic for spear, about 1,000 Marines and Iraqi forces, backed by battle tanks, fought their way into Karabilah in the volatile Anbar province.

During daylong battles, Marines and Iraqi soldiers fought "insurgents holed up in buildings within the city," Marine Capt. Jeffrey Pool said from Ramadi, the provincial capital.

"Coalition aircraft using precision-guided munitions destroyed these targets. Only buildings occupied by insurgents firing on Marines and Iraqi soldiers were bombed. Three buildings were confirmed destroyed," Pool said.

No American or Iraqi military casualties were reported.

In other violence, a suicide car bomber killed five Iraqis, including two civilians, and wounded 10 others in Fallujah, Pool said. The target was Fallujah's mayor and police brigade commander for the Interior Ministry's new public order unit, Maj. Gen. Mahdi Sabih, police said. He escaped unharmed.

Marines carried out two major operations in the area last month, killing 125 insurgents in the first campaign, Operation Matador, and 14 in the second, Operation New Market. Eleven Marines were killed in those two actions, designed to scatter and eradicate insurgents using the road from Damascus to Baghdad.

The new campaign began just before dawn in the desert wastes around Karabilah and nearby Qaim, a lawless town about 200 miles west of Baghdad that squats at the crossroads of an insurgent smuggling route leading into Iraq from neighboring Syria.

During Friday's assault, troops captured about 100 foreign fighters and discovered at least one car bomb factory, said Col. Bob Chase, chief of operations for the Second Marine Division. He said U.S. and Iraqi troops encountered some resistance, but didn't characterize it as significant.

Iraqi troops did not participate in the earlier anti-insurgent offensives but Chase said this time they not only fought alongside Americans, but used their language skills and knowledge of the area to spot foreign fighters.

Also near Ramadi, two Marines were killed in action Thursday when their vehicle hit a bomb during combat operations, the military said. The deaths raised to 13 the number of Marines killed in separate attacks around Anbar during the past week. Two sailors also have died.

At least 1,716 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.

In other violence, U.S. forces killed a 10-year-old boy Thursday while he was walking on a Baghdad street, police said. The U.S. military confirmed Friday that a child was killed during an "escalation of force" incident.

The Karabilah operation came one day after U.S. Air Force Brig. Gen. Don Alston called the Syrian border the "worst problem" in terms of stemming the influx of foreign fighters to Iraq.

U.S. military intelligence officials believe the area is the main entry point used by extremist groups such as Abu Musab al-Zarqawi's al-Qaida in Iraq to smuggle foreign fighters into the country. Syria is under intense pressure from Washington and Baghdad to tighten control of its porous 380-mile border with Iraq.

The area has been flush with insurgents in recent weeks. Marines carried out June 11 airstrikes that killed about 40 militants after a nearly five-hour gunfight on the outskirts of Karabilah. Insurgent in the area also killed 21 people -- beheading three of them -- thought to be a group of missing Iraqi soldiers. The bodies were found June 10.

At least 1,095 people have been killed since Prime Minister Ibrahim al-Jaafari's Shiite-led government was announced in late April.

According to an AP count, from April 26 through June 16, at least 136 vehicle bombings have killed at least 492 people and wounded at least 1,409. In addition, at least 10 suicide bombers, wearing explosives, have killed at least 188 people and wounded at least 493.

It is unclear how many insurgents have also died in that period, but they are thought to number more than 290.

Also Friday:

A car bomb killed four people and wounded another 15 outside a mosque in nearby Habaniyah, Pool said.

A suicide car bomber missed an Iraqi army patrol and slammed into a loaded fuel tanker in Baghdad, killing two people and wounding another six, police said.

Another suicide attacker died after a failed attempt to kill the Iraqi army commander in Tuz Khormato, 130 miles north of Baghdad. Seven people were wounded, police said.

The bodies of two Iraqis working for American forces were found near the town of Beiji, north of Baghdad. They had disappeared Monday.