Gunmen attacked a U.S.-run civilian convoy in Iraq's western desert and some personnel were unaccounted for, U.S. officials said Tuesday. Iraq's oil minister said a weekend bombing at a southern pipeline had cut oil exports by 30 percent.

The attack on the convoy came as one Russian worker was confirmed dead and two others abducted in another attack on foreigners working in Iraq.

The officials said the convoy was operated by a subcontractor of KBR, or Kellogg, Brown & Root (search), which is in turn a subsidiary of Halliburton (search). An unknown number of vehicles were destroyed in the attack near the town of Rutba, 230 miles west of Baghdad, the officials said.

A motorist said he saw six burned vehicles on the highway Tuesday, including one Iraqi civilian car caught in the crossfire. Witnesses said some convoy personnel were taken hostage.

Meanwhile, an American civilian was found dead with signs of trauma on the corpse near a highway overpass in Baghdad, the U.S. military said Tuesday.

The man, whose identity was not released, was not connected with the U.S. military or civilian government mission in Iraq, a military spokesman said. The body was discovered Saturday.

On Monday, three Russian employees of an energy company working at a power station south of Baghdad were returning to the capital when assailants fired on their car. The Russian Foreign Ministry said one worker was killed and the other two taken hostage.

An Iraqi citizen serving as a bodyguard and translator was wounded in the attack 18 miles south of Baghdad, said Yevgeny Loginov, spokesman for the Interenergoservis energy company.

Iraqi oil exports fell by 30 percent because of a weekend bombing on a southern pipeline, the oil minister said Tuesday. Ibrahim Bahr al-Ulloum said he expects the exports to return to normal levels within 24 hours.

The attack happened Saturday and damaged a 50-foot section of pipe. The oil minister said a fire at the site was still burning, but was "almost under control."

The attack signaled that such facilities in southern Iraq could now be a target for insurgents. Southern Iraq had been relatively quiet until a revolt last month by militiamen loyal to radical Shiite cleric Muqtada al-Sadr (search).

Late Monday U.S. forces clashed with al-Sadr's gunmen in the southern city of Kufa, killing at least five Iraqis and injuring 14 others, hospital officials said.

Kufa is near Najaf, where radical cleric Muqtada al-Sadr took refuge last month after U.S. authorities announced they were seeking him in the assassination last year of a moderate cleric.

U.S. troops have been involved in sporadic clashes with al-Sadr's forces for weeks. But the Americans have avoided an all-out assault on Najaf to avoid inflaming Shiite passions.

The new U.S.-appointed Najaf governor said Tuesday he will ask occupation authorities to defer murder charges against al-Sadr under a proposed deal to end the standoff with his Shiite Muslim militia.

Adnan al-Zurufi, who was appointed last week, proposed that the U.S.-led administration agree to delay legal proceedings against al-Sadr until after the Americans transfer power to a new Iraqi administration June 30.

In the northern city of Kirkuk, a homemade bomb exploded in a crowded market killing four Iraqis and injuring 23, a security official said.

The bomb exploded in a mostly Kurdish district, also destroying two cars, said Col. Anwar Mohammed Amin of the Iraqi security forces. Kirkuk is a mixed city of Kurds, Arabs and ethnic Turks.

Residents of the Shiite neighborhood Sadr City (search) on Tuesday began rebuilding the Baghdad headquarters of al-Sadr, which was destroyed in a tank and helicopter attack by U.S. forces about midnight Sunday.

At the urging of the al-Sadr's al-Mahdi Army (search), local Shiites brought bricks, cement and gypsum to the site. Parts of the building had already been repaired by midday.

"The city people pulled up their socks when they heard this sorrowful incident," Sheik Malik Swadi said. "Together they embarked on rebuilding the office."

Dutch officials, meanwhile, said two men have been arrested for a grenade attack that killed one Dutch soldier and wounded another in the southern Iraqi city of Samawah.

The casualties Monday night were the first for the Dutch since the Netherlands sent 1,300 soldiers to participate in the U.S.-led force.

Dutch officials said four soldiers were patrolling a bridge over the Euphrates when men on a scooter threw grenades at them. Two suspects were arrested shortly afterward by Iraqi police.