Doctor Hamdi al-Raoui said that the general hospital in the Sunni Muslim bastion, 100 km west of Baghdad, admitted eight dead Iraqis and 10 wounded in the skirmishes that flared from early in the morning.

A police captain said that the violence flared from about 6:00 am (0300 GMT), while an AFP reporter in the city heard explosions ringing out sporadically.

A US military official confirmed that clashes were ongoing, involving the "usual s}spects" namely zebel small arms and rocket propelled grenade fire, mortars and roadside bombs.

A second AFP correspondent embedded with the military said that three US marines were injured when a roadside bomb exploded as a convoy was passed through the Sunni Muslim bastion.

The blast happened shortly before 7:30 am (0430 GMT) in the capital city of the restive al-Anbar province.

Ramadi and nearby Fallujah are the two main bastions of rebel fighters in the Sunni province. Nine Marines were killed and a further nine injured during a security operation in the area on Saturday, the US military said.

A high level of military movement is taking place in Ramadi as US troops double their ranks to about 2,000 with the arrival of a new army battalion to join a marines battalion already based in the city.

In Hilla fifteen Iraqis died and another 20 were wounded in an exchange of gunfire south of Baghdad, hospital sources said, while the US military reported killing five suspected rebels during clashes.

"The hospital admitted 15 dead and 20 injured," said Abdel Razzak al-Janabi, the head of Iskandariyah hospital, 45km south of the Iraqi capital.