In northern Baghdad, a large water main was hit by an explosion early Sunday, flooding streets and cutting supplies to a part of the city. Witnesses saw two men on a motorbike leaving a bag of explosives and detonating it minutes later.
A mortar attack at a prison outside Baghdad killed three Iraqis and wounded 61, and a Danish soldier was killed by a gunshot near the southern city of Basra. Attacks continued against U.S. forces.
The crumbling network of pipe began pumping oil to Turkey on Wednesday, but the explosion early Friday near Baiji, 125 miles northeast of Baghdad, cut it off completely, acting Iraqi oil minister Thamer al-Ghadaban said in the capital.
L. Paul Bremer, the U.S. civilian administrator of Iraq, said the country was losing $7 million a day with the pipeline out of operation.
Police Brig. Gen. Ahmed Ibrahim, the new Iraqi police commander, vowed to pursue "a group of conspirators who received money from a particular party" to blow up the pipeline. Al-Ghadaban also blamed saboteurs.
But a U.S. military spokesman said it was too soon to say whether the explosion was an accident or sabotage.
"Until it's cooled off, nobody can say exactly what happened," said Lt. Col. William MacDonald, of the 4th Infantry Division based in Tikrit.
The 600-mile pipeline has a diameter of 46 inches. It runs from the northern Iraqi city of Kirkuk to the Turkish city of Ceyhan and handles all oil exports to Turkey.
Iraq has the world's second-largest proven crude reserves, at 112 billion barrels, but its pipelines, pumping stations and oil reservoirs are dilapidated after more than a decade of neglect. Northern Iraq, site of the giant Kirkuk oil fields, accounts for 40 percent of Iraq's oil production.
Al-Ghadaban said it would take several days to get the pipeline working again.
The Danish army reported one of its soldiers died from a gunshot after stopping a truck of Iraqis on Saturday near Basra in southern Iraq. The soldier was the first Dane killed since Denmark sent about 400 soldiers this summer to join the stabilization force around Basra.
Two Iraqis died in the shootout, one was wounded and six were arrested, the Danish army command said in Denmark.
U.S. military spokesman Spc. Anthony Reinoso said someone fired two mortar rounds at the notorious Abu Ghraib prison Saturday night, killing three Iraqis and wounding 61. He didn't know whether the casualties were guards or prisoners, or who was behind the attack.
Two U.S. soldiers were shot Saturday coming out of a Baghdad restaurant, but were able to drive themselves to a medical facility for treatment. Reinoso had no further details.
Further north in Mosul, the police chief survived an assassination attempt, taking two bullets to the leg, the U.S. military reported. Two people, apparently bodyguards, were killed and 14 were wounded, said spokesman Sgt. Danny Martin.
"It was an ambush at an intersection," Martin said.
Martin, who called the official "Chief Mohammed," said his condition was not life-threatening.
An American soldier also was wounded by shrapnel Saturday when a patrol of Abrams tanks, armored personnel carriers and Humvees was ambushed near Baqouba, 45 miles northeast of Baghdad.
The attackers detonated a roadside bomb made of four 155 mm artillery shells, then opened fire with rocket-propelled grenades and automatic weapons, said Capt. Jon Casey of the 4th Infantry Division, who was on the patrol.
"We engaged them with our own automatic weapons and called in helicopter support," he said. "We had no further contact and secured the area."
Soldiers from the 4th Infantry Division conducted 11 raids across north-central Iraq and detained five people, including three suspected regime loyalists and a man who allegedly had threatened to kill a U.S. soldier, MacDonald said.
The division also announced the detention of Said Ali al-Karim, a Baqouba cleric known as "the prophet" it said had urged violence against Americans and financed Saddam loyalists fighting U.S. forces.
It said al-Karim, which it described as "a counselor to Saddam Hussein," was arrested Monday and could be charged with inciting violence, funding attacks and possessing illegal weapons. It gave no explanation for the delay in reporting his arrest.