Aljazeera, quoting an Iraqi journalist, said two of Monday's attacks took place simultaneously. Three bombs hit a US military headquarters, while a fourth targeted a US military convoy.
Clashes erupted later between fighters and the US troops in the city damaging a number of houses', the journalist told Aljazeera. However, no civilians were injured as they had left before the clashes took place, he said.
A spokesperson for the US marines said on Monday three of their soldiers were wounded in the attack, which occurred outside Camp Gannon, a base in al-Qaim, about 300km west of Baghdad in Anbar province.
The al-Qaida-linked group of Abu Musab al-Zarqawi said in an internet statement it carried out the car bomb attacks.
"The martyrdom-seekers of the al-Qaida brigades carried out three heroic operations against American bases (in al-Qaim) causing them wounds" on a large scale, said the statement on a website. The authenticity of the claim, or the website, could not be independently verified.
Clashes broke out soon after
the anti-US attack in al-Qaim
"What we have right now is three confirmed suicide vehicle-borne improvised explosive devices," First Lieutenant Kate VandenBossche said.
"The blast was incredible," Yasir al-Hadithis, a police lieutenant, said, adding that US helicopters were flying over the scene of the attack.
Clashes broke out between fighters and US and Iraqi forces immediately after the explosions.
Three civilians, including an eight-year-old boy and an old man, were wounded in ensuing clashes, but it was not clear if they involved US troops, a hospital source said.
"What we have
right now is three confirmed suicide vehicle-borne improvised
First Lieutenant Kate VandenBossche,
US Marines spokesperson
Al-Qaim has seen frequent outbreaks of violence in recent months. US forces believe weapons and fighters enter Iraq from Syria across the border post near the town.
Syrian authorities deny the charge.
In other incidents, in Mosul, 400km north of Baghdad, a member of the provincial council was shot dead by an armed group outside the city's main hospital, US forces said on Monday.
Ajil Muhsin Ajil was in his car near the Mosul General Hospital on Sunday when a group of armed men leaped out of another car parked nearby and shot him. His driver was also killed.
It was the second assassination of a provincial politician in the past three weeks. Last month, General Walid Qashmula, the director of the province's anti-corruption office, was killed in a car bomb attack on his convoy.
Anti-US forces in Iraq frequently target officials seen as collaborating with US authorities or working with the US-backed interim government.
The governor of Mosul, also from the Qashmula family, was assassinated in July last year.