A suicide bomber driving a truck loaded with TNT and toxicchlorine gas crashed into a police checkpoint in western Ramadi on Friday,killing at least 27 people and wounding dozens, police in the Anbar provincialcapital said.

In the deep south of the country, the Basrapolice commander said the type of roadside bomb used in an attack that killedfour British soldiers on Thursday had not been seen in the region previously.

Two more of the bombs were discovered planted along routesheavily traveled by U.S. andBritish diplomats in Basra.

The bombing in Anbar province marked the ninth use of suicide chlorine bombsin the sprawling, mainly desert territory that has been a stronghold of theSunni insurgency.

Police Maj. Mohammed Mahmoud al Nattah, member of the Anbar Salvationcouncil, told state-run Iraqiya television the bomber hit a residential complexand dozens of wounded were taken to the Ramadi hospital.

Police opened fire as the suicide car bomber sped toward a checkpoint, threemiles west of the city, according to police Col. Tariq al-Dulaimi. Nearbybuildings were heavily damaged and police were searching the rubble for morevictims.

Dr. Hameed Jaafi, the director of Diwaniyah Health Directorate, said anAmerican helicopter fired on a house in the Askari neighborhood, seriouslywounding 12 people as the early morning assault began.

Bleichwehl said there were no U.S. air strikes either byhelicopters or planes.

Also Thursday, the U.S.military confirmed an American helicopter carrying nine people had been downedsouth of Baghdadand that four were injured.

An Iraqi army official, speaking on condition of anonymity because ofsecurity concerns, said the helicopter crashed after coming under fire near theSunni insurgent stronghold of Latifiyah, about 20 miles south of Baghdad. The U.S. militarydid not confirm that account.

It was the ninth U.S.helicopter to go down in Iraqthis year.

The four British soldiers — including two women — were killed Thursday asthe American military announced the deaths of eight more U.S. soldierssince Tuesday.

The Basra region police commander,al-Moussawi, said two similar bombs had been discovered Friday morning; one wasdiscovered on the road leading to BasraPalace, the compound that houses aBritish base and the British and U.S. consulates. A second wasuncovered in the western Hayaniyah district where Thursday's attack occurred.

One U.S. soldier died andtwo were wounded in a roadside bombing Thursday in restive Diyala provincenorth of Baghdad,the military said. Four others died Wednesday in two roadside bomb explosionsin southern Baghdad and north of the capital, while a fifth was killed bysmall-arms fire in the eastern part of the city. Two other soldiers were killedby small-arms fire on Tuesday — one in eastern Baghdad and another on foot patrol in thesouthern outskirts of the capital.