BAGHDAD, March 18: Insurgents in Iraq killed seven more US troops as security forces said on Sunday they expected more chemical attacks after three dirty bombs left two policemen dead and 350 civilians sick.

Almost exactly four years after the US-led invasion, American casualties are still mounting as US and Iraqi forces battle to quell the insurgent and sectarian violence gripping the country.

The US military said four troops were killed on Saturday when a roadside bomb ripped through a patrol in west Baghdad.

Another soldier was killed the same day when a foot patrol was targeted by a bomb in the south.

A sixth soldier was killed and five wounded, also on Saturday, in a bomb blast in Diyala province, where attacks are on the rise as insurgents focus on areas beyond the reach of an intensive security operation under way in the capital.

A marine also died Saturday during combat operations in Anbar province, an insurgent stronghold west of Baghdad, the military said without elaborating.

Insurgents detonated three trucks filled with toxic chlorine gas, putting at least 350 Iraqi civilians in hospital and killing two policemen, the US military reported, adding that six American soldiers also fell sick.

Two of the attacks came just south of the town of Fallujah and one was northeast of the nearby city of Ramadi, both hotbeds of Al Qaeda militants.

“This is the doing of terrorist organisations in Ramadi and Fallujah,”Dabbagh told a news conference in Baghdad. “Public opinion in Ramadi is going against these groups, and so they threaten the people of Anbar.

14 IRAQIS KILLED: In other violence in Iraq on Sunday, 14 people were killed, six of them in a car bombing in a popular market near Baghdad's Shia militia stronghold of Sadr City.

Insurgents continue to carry out assaults in Baghdad despite the presence of 90,000 US and Iraqi troops on the streets as part of Operation Fardh al-Qanoon (Imposing Law), which was launched on Febr 14 in a bid to quell sectarian violence.

US military spokesman

Rear Admiral Mark Fox acknowledged at the joint news conference with Dabbagh that as general violence in the capital has been reduced, the number of car bombings has risen.

GATES: “We are taking down the networks that produce these car bombs. We are taking down car bomb factories,” he added.

But US Defence Secretary Robert Gates said it was too soon to know whether the recent “surge” of thousands of additional US troops was having an impact on the rampant violence.

“I think that the way I would characterize it is, so far so good,” Gates told CBS television, adding that “it's very early” to make a more definitive assessment.

Iraqi security forces meanwhile seized a cache of weapons, including a sniper rifle, and arrested seven suspects in a raid on the house of leading Sunni member of parliament Dhafer al-Ani.

Iraqi military spokesman Brigadier General Qassim Mussawi said the troops found “65 Kalashnikov rifles and other weapons and seized four vehicles,” which contained traces of explosives.

Ani is a former spokesman for Iraq's biggest Sunni faction, the Islamic Party, which forms part of the governing coalition.—AFP