American soldiers rounded up 14 members of a family said to be a pillar of support for Saddam Hussein in raids Tuesday, including a Republican Guard (search) officer and one of the deposed dictator's bodyguards.

West of Baghdad, guerrillas attacked an American convoy with three roadside bombs, killing one U.S. soldier and wounding two. But the commander of American forces told The Associated Press the stakes are too high to let casualties deter the mission of pacifying Iraq.

"Every American needs to believe this: that if we fail here in this environment, the next battlefield will be the streets of America," Lt. Gen. Ricardo Sanchez (search) said. "Every soldier ... understands the impact to America and to the global war on terrorism of his duty here."

On the outskirts of Tikrit (search), Saddam's hometown, U.S. soldiers captured 14 men in a three-hour operation. All were members of the same family, which was a key supporter of Saddam's regime, said Lt. Col. Steve Russell.

"They were trying to support the remnants of the former regime by organizing attacks, through funding and by trying to hide former regime members," he said.

Russell said the Republican Guard officer was a divisional chief of staff. He and the bodyguard were on a U.S. black list of Iraqis considered major catches but not as important as the top 55 most-wanted figures.

Tikrit has been a center of the hunt for Saddam, who the military believes is now moving every three to four hours.

The Army had been watching the family for weeks after collecting intelligence indicating it had been involved in recent attacks on soldiers, Russell said. Coalition forces moved in Tuesday when they thought they could catch the most people.

About 250 soldiers surrounded and searched 20 homes, Russell said, carrying out a safe, photographs and computers.

North of Baghdad, a dark cloud blotted out the sun as flames shot 200 feet into the air from a burning oil pipeline. Iraqi firefighters later doused the blaze with chemicals.

It was unclear whether the fire, 12 miles north of Baghdad in an area known as Taji, was an accident or the work of saboteurs. Guerrillas have hit many pipelines to slow U.S. reconstruction efforts and delay the resumption of Iraq's oil exports.

Two M-1 Abrams tanks and three soldiers crouched in firing positions along a highway next to the pipeline, which blazed from three holes. They fired warning shots to keep journalists away, and initially chased off Iraqi firefighters.

"They were very hostile," said Lt. Hasannein Mohammed of the fire department.

An AP photographer saw another pipeline blaze northwest near the town of Haditha. The fire at a junction box burned out of control, and neither Iraqi nor American authorities were at the scene.

The U.S. soldier killed Tuesday morning was riding in a Humvee in Ramadi, a site of frequent attacks on American troops 60 miles west of Baghdad. A military spokesman said the convoy was hit by three roadside bombs wired to explode one after another. Two soldiers were wounded.

The death brought to 58 the number of U.S. troops killed in action since May 1, when President Bush declared major combat over.

Another American soldier was found dead in his bunk Tuesday at a Ramadi base; no cause of death was reported. In Mosul, in the far north of the country, the military reported a soldier died when his Humvee collided with a taxi.

Sanchez said the attacks on Americans are coming from a variety of sources.

"Clearly I think it's the former regime loyalists and the foreign fighters-slash-terrorists. Those are my two top priorities right now," he said.

Sanchez said the groups have "very selfish interests."

"It's to re-establish their own power base so they can continue with the repressive controls they used to have on this country," he said. "And that's not going to happen."