Meanwhile in Baghdad, tension remains high as resentment towards US-led forces simmers following an operation that has inflamed the capital’s Shia population.

Acting Oil Minister Thamer Ghadhban blamed "sabotage" and technical problems on Saturday for stopping oil flowing through a recently reopened northern export pipeline to Turkey. He said a fire, probably caused by a bomb, had closed the pipeline to the Turkish port of Ceyhan.

"The fire is under control and will be put down," he said, adding it would take at least a week to repair the pipeline. Ghadhban said the explosion occurred early Friday morning 20km north of the pumping station at Baiji.

Police ambushed

Elsewhere, an ambush south of the city of Mosul left two guards dead and a senior police officer seriously injured, Aljazeera’s correspondent reported on Saturday. Another guard was also injured in what is presumed to be an attack on perceived collaborators.

A US soldier was wounded earlier Saturday morning when his patrol came under attack in a village near the town of Ba'quba, northeast of Baghdad, the US Army said.

A US soldier searches Iraqis in 
Baghdad where tension is rising

The attackers used small arms fire and rocket-propelled grenades, the Army said. The patrol returned fire but there were no reports of Iraqi casualties.

Earlier, a US patrol came under attack in the Al-Qadissiya district of Samara, north of Baghdad, when Iraqi fighters fired a rocket-propelled grenade, an Aljazeera correspondent said. A US tank was damaged but no casualties were reported.

Shia angry

In a Baghdad suburb, tensions simmered three days after a US helicopter tried to bring down a religious flag on a communications tower.

Shia residents of Sadr City have rejected a US apology for provoking Wednesday's protest and vowed more violence unless US troops withdrew from the district.

"We were happy at first when the Americans came. Now they should keep out, no one wants them around," shop-owner Jasm Kathai, told Reuters. "What they did to the flag was a grave insult to Islam. There will be consequences.”

In the south of the country, British troops reportedly arrested three or four Iraqis during a raid in Basra - two days after a roadside bomb killed a British soldier and wounded two others in the city.