THREE suicide bombers driving trucks rigged with tanks of toxic chlorine gas struck targets in heavily Sunni Anbar province in Iraq, killing at least two people and sickening 350 Iraqi civilians, the U.S. military said Saturday.

Meanwhile, a roadside bomb killed four U.S. soldiers patrolling western Baghdad on Saturday, the military said.

The Anbar assaults came three days after Prime Minister Nouri al-Maliki, a Shiite, traveled there to reach out to Sunni clan chiefs in a bid to undermine tribal support for the insurgency.

The violence started about 4:11 p.m. Friday when a driver detonated explosives in a pickup truck carrying chlorine at a checkpoint northeast of the provincial capital of Ramadi, wounding one U.S. service member and one Iraqi civilian, the military said in a statement.

Two hours later, a dump truck exploded in Amiriyah, south of Fallujah, killing two policemen and leaving as many as 100 residents with symptoms of chlorine exposure ranging from minor skin and lung irritations to vomiting, the military said.

Iraqi authorities said at least six people were killed and dozens wounded when the truck blew up in a line of cars waiting at a checkpoint.

Four other bombings have released chlorine gas since Jan. 28, when a suicide bomber driving a dump truck filled with explosives and a chlorine tank struck a quick-reaction force and Iraqi police in Ramadi, killing 16 people.

The most recent such attack occurred Feb. 21 in Baghdad, killing five people and sending more than 55 to hospitals.

A previously unannounced suicide car bombing in Ramadi involving chlorine killed two Iraqi security officers and wounded 16 other people, including 13 civilians, Feb. 19, the military said Saturday.

Chlorine, which irritates the respiratory system, eyes and skin at low exposure and can cause death in heavier concentrations, is easily accessible. It is used for water purification plants, bleaches and disinfectants.

The primary effect of the chlorine attacks has been to spread panic. Although chlorine gas can be fatal, the heat from the explosions can render the gas nontoxic. Victims in the recent chlorine blasts died from the explosions, and not the effects of the gas.

(SD-Agencies)