One member of the Iraqi security forces is believed dead after U.S. troops mistakenly fired at him and several others at a checkpoint north of Baghdad (search), FOX News has learned.

Details of the shooting were not immediately available. Two other Iraqis were injured, Pentagon officials said, and the incident was under investigation.

The friendly fire shooting comes less than a month after U.S. forces fired on a vehicle carrying freed Italian hostage Giuliana Sgrena (search). An Italian intelligence officer was killed trying to shield the journalist, who was injured in the March 4 incident.

Contradicting versions of what transpired led to diplomatic tensions between Washington and Italy, one of America's staunchest allies in the Iraq war, and renewed calls for pulling Italian troops out of the country.

The U.S. military said that the vehicle carrying Sgrena and the intelligence officer was traveling at a high rate of speed on a road leading to Baghdad's airport. The car's driver repeatedly failed to obey signs warning cars to slow down and stop at the checkpoint, the military said.

The Italian government insisted that U.S. troops were given word that the hostage rescue was under way, and that they should expect the vehicle.

A joint U.S.-Italian probe into why the American troops opened fire is under way.

FOX News' Nick Simeone and Mike Emanuel contributed to this report.