Baghdad, Iraq ? U.S. forces widened their operations against insurgents in northern Iraq on Tuesday, launching an attack on the Euphrates River stronghold of Haditha only days after evicting militants from Tal Afar. Residents also reported American air strikes in the same region near Qaim.

The Americans called in bombing raids in Haditha, 140 miles northwest of the capital. They captured one militant with ties to al-Qaida in Iraq and killed four others.

In the volatile city of Qaim, about 80 miles northwest of Haditha, residents said clashes broke out between insurgents and coalition forces. The U.S. military did not confirm the air strike.

In the south, a roadside bomb killed four people near Basra – an attack that was a twin to a deadly bombing in the area last week. Iraqi police said the dead were four American contract workers, but U.S. officials were unable to confirm the nationalities of the victims. Last Wednesday, a roadside bomb near Basra hit a passing convoy of U.S. diplomatic security guards, killing four Americans.

‘Horrible things’

A U.S. Army commander said Tuesday that extremist fighters battling for control of Tal Afar in northern Iraq had committed atrocities against civilians, including beheadings, torture and the booby-trapping of a murdered child’s body.

“The enemy here did just the most horrible things you can imagine – in one case murdering a child, placing a booby trap within the child’s body and waiting for the parent to come recover the body of their child and exploding it to kill the parents; beheadings and so forth,” Col. H.R. McMaster, commander of the 3rd Armored Cavalry Regiment, said in an interview from Tal Afar with reporters at the Pentagon.

Iraqi Army soldiers take cover in a drainage ravine after shooting broke out at a grain silo Tuesday in Tal Afar, Iraq, 260 miles northwest of Baghdad. U.S. commanders said more than 400 suspects had been captured during the offensive to retake the northern town of Tal Afar.

Criticizing Syria

McMaster said Tal Afar is not yet under the control of the 5,000 Iraqi government forces and 3,500 to 3,800 U.S. troops that have been fighting together there for the past two weeks. Tal Afar lies about 50 miles from the Syrian border.

Iraqi Foreign Minister Hoshyar Zebari, speaking in Washington, said Syria was playing a “dangerous game” in allowing insurgents to penetrate Iraq from Syrian territory.

“Don’t think you can benefit from our difficulties. It may be for the short term, but for the long term it might backfire on you,” he warned Iraq’s neighbor to the West.

Bush also renewed criticism of Syria, accusing it of doing too little to control the flow of fighters across the border.

“The Syrian leader must understand we take his lack of action seriously,” he said. “The government is going to be more and more isolated.”

Syrian officials say they are doing all they can and deny they offer sanctuary to insurgents.

During Sunday’s operation in Tal Afar, Iraqi Prime Minister Ibrahim al-Jaafari closed the closest Syrian border crossing. Iraqi officials say most of the insurgents they flushed out of the city were foreigners who entered the country from Syria.

Other violence

After the raid Tuesday on Haditha, Associated Press Television News videotape showed at least three houses that residents said were demolished in the U.S. air strike. The U.S. military said American jets destroyed a vehicle used by one of the insurgents. Haditha is one of a series of towns in the Euphrates River valley controlled by militants.

U.S. forces have been conducting random raids and air strikes in the region that target insurgent safe houses and weapons caches.

In Baghdad, insurgents shelled the heavily fortified Green Zone, firing two mortar rounds that exploded near a military hospital inside the protected area that houses the U.S. Embassy, the Iraqi government and parliament and other foreign missions. There were no casualties.

Security in place for event

In the Shiite holy city of Karbala, 50 miles south of Baghdad, police banned trucks from entering the city as of Tuesday and said they would prohibit cars from entering beginning Thursday. The move was a precaution against bomb attacks on 3 million pilgrims expected for a key religious festival early next week.

The stringent security measures in Karbala reflect fears that birthday celebrations for Imam al-Mahdi al-Muntadhar, a 9th-century religious leader, could be marred by attacks by Sunni Arab insurgents, many of whom view Shiites as heretics.

Insurgent attacks on similar celebrations throughout the country have left hundreds dead in the past two years, prompting authorities to impose increasingly restrictive measures.

The security plan involves roughly 5,400 provincial policemen, including police commandos and about 750 Iraqi soldiers, Karbala police chief Brig. Karim Al-Hasnawi told The Associated Press.

“The main duty for the army battalion and the 1,400 police special forces will be to set up check points on a 25-mile radius around the city to secure the main highways leading to the city and the surrounding farming areas,” said Al-Hasnawi.