Seven precision-guided missiles were fired at heavily armed insurgents who were stopping and searching civilian cars at gunpoint near Karabilah, close to the volatile town of Qaim, the Marines said in a statement.
The insurgents were armed with AK-47 assault rifles, medium machine guns and rocket-propelled grenade launchers and had "set up a barricade on a main road to the city and were threatening Iraqi civilians," the military said.
U.S. warplanes backed by helicopters launched air strikes that began at 11:40 a.m. and ended at 4 p.m. "once all the targets were destroyed," the military said. Approximately 40 insurgents were killed and there were no Marines casualties.
"The coalition aircraft and fighter jets and attack helicopters from the 2nd Marine Aircraft Wing attacked the insurgent compound and surrounding area targeting the armed men," the statement said. "There are no reports of civilian casualties or collateral damage."
In other recent developments:
A former commando wearing a uniform blew himself up during roll call at the heavily guarded headquarters of an elite Iraqi police unit Saturday, officials said, as attacks in and around Baghdad killed at least 23 people.
Interior Minister Bayan Jabr, meanwhile, said an ongoing Iraqi-led offensive to weed out militants in the capital was a success and expressed confidence that the Shiite-led government would bring security to the country within six months.
The attack at the two-story Baghdad headquarters of the Wolf Brigade followed weeks of accusations against the Shiite Muslim-dominated force by Sunni Arab leaders, who accuse it of kidnapping and killing Sunnis, including clerics.
Jabr said the attacker was a former Wolf Brigade member who was targeting the commando force's commander, Brig. Mohammed al-Quraishi.
"Today's attack does not constitute an infiltration of the police forces," Jabr said. "The only thing left of the bomber was his head and feet."
Three people were killed in the blast, Jabr said, adding that police were searching for two of the suspect's former colleagues. A witness, Maj. Falah al-Mahamdawi, said five people were killed and seven wounded. The discrepancy could not immediately be reconciled.
Gunmen also opened fire on a minibus in Diyara, 30 miles south of Baghdad in the so-called Triangle of Death, killing at least 11 Iraqi construction workers employed at government and U.S. bases, police said.
In Baghdad, gunmen in a speeding car attacked an Interior Ministry commando convoy in western Baghdad's Mansour area, killing three Iraqi forces, police said.
Another suicide car bomber blew himself up Saturday in front of the Slovakian Embassy in southeast Baghdad, injuring four people, according to Iraqi and Slovak officials. Slovakia has 109 soldiers in Iraq mostly for de-mining efforts.
It was unclear how the attacker managed to enter the tightly guarded compound in eastern Baghdad's Bab Sharqi neighborhood with his explosives undetected, but his police uniform may have helped him avoid the stringent checks in place.
People entering the compound, which also houses the 10-story Interior Ministry building, must go through metal detectors and be searched by policemen and dogs.
Al-Mahamdawi said the attacker was disguised as a policeman and detonated explosives during a roll call for new commandos.
"I was inside the headquarters building when the explosion took place," al-Mahamdawi said. "Then I saw five dead bodies lying on the ground plus seven injured people, most of them are policemen."
"There was a group of newly graduated commandos gathered in the yard at the time of the explosion," he added. It was unclear if the bomber was standing among the graduates or was nearby.
It was uncertain what motivated the attack. Such violence is usually associated with the Sunni struggle for a role in the country's political process. Sunnis, who comprise only 15 percent to 20 percent of Iraq's 26 million people but dominated the country under Saddam Hussein, resent the rise to power of the majority Shiite community and the U.S.-allied Kurds.
This is believed to be a major factor in the continuing insurgency in Iraq that has killed at least 934 people since the new Shiite-led government was announced April 28.
Sunni Arab leaders have criticized the offensive in Baghdad, saying it has been particularly heavy handed with the minority.
"I'm worried about the way the recent security plan has been implemented," Iraq's Sunni Arab Vice President, Ghazi al-Yawer, told the London-based, pan-Arab Al Hayat newspaper.
"That's why I call for not breaking into people's homes without a legitimate reason and for depending on thorough security information and not on biased information," he added.
Jabr said that more than $6 million had been confiscated, 36 militants killed and 1,318 people arrested, including eight foreigners — all Arabs, in the ongoing counterinsurgency campaign dubbed "Operation Lightning," which will enter its third week on Sunday.