The military will open an investigation into the shooting of a wounded, unarmed Iraqi prisoner in a mosque caught on videotape by an NBC cameraman during the recent fighting in Fallujah.

According to the cameraman, Kevin Sites of NBC, three other prisoners had been shot in similar fashion a day after they were wounded.

A different unit of American Marines wre reportedly under fire from the mosque which was stormed and captured by U.S. troops. The Marines said the insurgents had used rocket-propelled granades and AK-47s to attack the Americans.

Just before the man was shot, a conversation is heard on the tape between two marines who argued that the wounded man was faking his death.

'He's (expletive) faking he's dead!' one Marine says.

'Yeah, he's breathing,' answers another.

'He's faking he's (expletive) dead!' the first man repeats.

The man is then shot in the upper body, probably in the head as blood splatters around the body.

'He's dead now,' a Marine says emphatically.

According to Sites who was travelling with the Marines 3rd Battalion, 1st Regiment, a member of the same unit had been killed the day before when tending to the body of a dead insurgent that had been booby-trapped.

Lieutenant General John F. Sattler indicated the investigation would be thorough. 'We follow the law of armed conflict and hold ourselves to a high standard of accountability,' he said. 'The facts of this case will be thoroughly pursued to make an informed decision and to protect the rights of all persons involved.'

The investigation will be headed by Lieutenant Col. Bob Miller who indicated, 'Any wounded - in this case insurgents - who don't pose a threat would not be considered hostile.'

The name of the Marine shown on the videotape has not been released to the press.