Two US soldiers and a Marine were killed in western Iraq, the military said yesterday.

A Marine with the 2nd Regimental Combat Team, 2nd Marine Division, II Marine Expeditionary Force was killed by a roadside bomb Monday in the town of Karabilah, near the Syrian border, the first announced US death in Operation Iron Fist, a major sweep of the area that began over the weekend.

A soldier assigned to 2nd Regimental Combat Team, 2nd Marine Division, II Marine Expeditionary Force (Forward), was killed by a roadside bomb Monday while conducting combat operations in Haqlaniyah, the military said.

Two months after a previous bid to push Islamist fighters out of the area, Operation River Gate was intended to stop al-Qaeda operating in the city and two nearby towns, Haqlaniya and Barwana, and to "free the local citizens from the terrorists' campaign of murder and intimidation," it added.

The towns are among several in the Euphrates valley where local people have said fighters have taken control and imposed Taliban-style Islamic rule, despite frequent offensives by US forces.

During Operation Sword in August, about 1,000 US troops fought militants in Haditha and its neighbouring towns, 200 km northwest of Baghdad.

Some 2,500 US troops with some Iraqi soldiers were taking part in the latest crackdown, making it the biggest of the year in Anbar, the sprawling desert province of western Iraq, the military said in its statement.

Separately, about 1,000 troops have been fighting al-Qaeda militants near Qaim on the Syrian border, a further 120km to the west, since Saturday in Operation Iron Fist.

"There are now two major operations going on simultaneously," a US military spokesman in Baghdad said.

In its statement on Haditha, the military said: "The operation's goal is to deny al-Qaeda in Iraq the ability to operate in the three Euphrates River Valley cities and to free the local citizens from the terrorists' campaign of murder and intimidation of innocent women, children and men.

Meanwhile, a suicide car bomber drove into Baghdad's heavily fortified Green Zone complex with a convoy of other vehicles on Tuesday and blew up, killing three people and wounding six, Iraqi police said.

The vehicle entered the Green Zone, which houses the US and British embassies and the Iraqi government, by an entrance used by Iraqi employees, journalists and others to enter the complex.