An American civilian contractor was killed Tuesday when a bomb was detonated under the truck he was driving north of Tikrit (search), the U.S. military said.

The contractor was employed by Kellog Brown & Root (search), a subsidiary of Halliburton (search), a Houston-based oilfield-services and construction company. Halliburton is the former company of Vice President Dick Cheney which has major contracts for reconstruction in both Iraq and Afghanistan.

Maj. Brian Luke, of the 4th Infantry Division, said the five vehicle convoy was traveling from Baghdad, 120 miles to the south when it was attacked.

Kellog Brown & Root had been doing work at the Baiji refinery and pipeline terminus about 50 kilometers (30 miles) north of Tikrit, the hometown of deposed dictator Saddam Hussein.

The military said the destination of the convoy was not immediately known, and that the name of the civilian was being withheld until relatives were notified.

Lt. Col. William MacDonald, also of the 4th Infantry, said the contractor died after being taken to a U.S. military field hospital at an air base north of Tikrit.

By midafternoon Tuesday, American forces were well into a fourth straight day without losing a U.S. soldier to hostile fire, after a two week period in which American forces were being killed at a rate of nearly one a day.

All of the deaths were occurring in the Sunni Triangle, the region north and west of Baghdad where support for Saddam's ex-regime remains especially strong. Tikrit, where Saddam's slain sons Uday and Qusay were buried Saturday, sits in the region and has proven especially hostile to the American occupation.

The sons died in a shootout with American forces July 22 in the northern city of Mosul, where they were hiding in a villa. The villa's owner was believed to have betrayed the brothers. The informant, whomever it was, has already been paid a US$30 reward for the information and taken into hiding outside Iraq by American authorities.

It was not immediately clear if the civilian contractor killed Monday was the first to die in Iraq, but he was certainly among the first.

Cheney's former company already has garnered more than $600 million in military work related to the wars in Afghanistan and Iraq, and potentially could earn billions more without having to compete with other companies.

As the Army's sole provider of troop support services, Kellogg Brown & Root has received work orders totaling $529.4 million related to the two wars under a 10-year contract that has no spending ceiling.

Rather than put the Iraq work up for bidding, the government has used the 2001 Halliburton contract to place the various work orders in Iraq, prompting criticism from some Democrats that Cheney's former company is receiving favored treatment.