The U.S. military is investigating a report that American soldiers opened fire with a machine gun on a taxi, killing four Iraqi civilians, including a 7-year-old boy, and wounced the driver last week in Saddam Hussein's (search) hometown.

Iraqi police in the northern town of Tikrit (search), found the bullet-riddled car and took the wounded driver, Ibrahim Allawi, to the hospital.

Allawi said he was driving four passengers in his taxi on the evening of Jan. 3 when he was caught behind a convoy of four Humvees on a road leading to the main highway through Tikrit.

Soldiers in the last Humvee (search), he says, directed him to pass the convoy. When he had nearly cleared all the vehicles, machine gun fire struck his taxi, he said.

The fire came from the lead vehicle in the convoy, Allawi said from his hospital bed.

The U.S. military is investigating the shooting, but has not yet reached any conclusion, said Maj. Josslyn Aberle, a spokeswoman for the Army's 4th Infantry Division, which is based in Tikrit.

The Iraqi officers said they believed his account and expressed frustration by what they said was a delayed response to the incident by U.S. authorities.

U.S. soldiers who went to the scene found a blue Chevrolet Caprice "hit by multiple bursts of heavy-caliber machine gunfire," and several dead Iraqis, said Lt. Col. Steve Russell, a battalion commander in Tikrit. The incident was a "human tragedy," he added.

"Our soldiers were not involved in this incident," Russell said. "But it's possible that the damage to the vehicle could have come from coalition forces given the (type of) damage."

The incident, which people refer to as "the car slayings," adds to already high tension in Tikrit, a major center of attacks against coalition forces.

In a raid on Friday that was aimed at Saddam loyalists, U.S. soldiers kicked open doors and dragged men and teenage boys from their beds. Thirty suspects were arrested.

"The misconduct (of American soldiers) will make people turn against them, more than they already are," Allawi said.

He was particularly incensed that his attackers immediately left the area after the shooting: "I am a peaceful civilian, why would they attack me?" he said. "And then they leave me and run."

People in a nearby village heard the shots and went to investigate, finding the passengers dead and Allawi critically wounded with bullet wounds to the stomach, hand and shoulder, police said. There was no sign of a convoy.

Those killed were later identified as Intissar Kadhem, 40; her 7-year-old son Ahmed Jawad; Rasheed Hamoud Taha, 40; and Abdullah Hamoud, 53.

U.S. forces are supposed to report any shooting incident, including those involving civilians. Col. William Darley, a spokesman with the Baghdad-based Coalition Joint Task Force, said he had not heard of any U.S. military involvement in the incident, except by those who went to the scene later.

Any convoy going from Baghdad to northern cities like Mosul and Kirkuk must drive through Tikrit.

"The people of Tikrit expect the Iraqi police and the coalition forces to find an answer to this," Russell said, "I believe we have a moral obligation to find out what occurred."