The vehicle, reportedly carrying charge d’affaires Stewart Henderson, came under friendly fire after it apparently attempted to pass an American convoy, said U.S. Lt.-Col. Barry Johnson, spokesman for the multinational force in Iraq.

“There were two convoys. We’re looking at the reason shots may have been fired,” said Johnson. “I haven’t seen the final report.”

However, military convoys carry markings warning that the common procedure is not to pass, a precaution against suicide bombers, he noted.

If vehicles fail to respond to hand signals followed by warning shots, “shots may be fired at the vehicle,” he said.

Canadian and U.S. officials are investigating.

“It’s certainly under review, to see what procedures, what steps were taken and who made a mistake, to make sure this wouldn’t happen again,” said Johnson.

CTV News said the Canadian vehicle was travelling alone, en route from the British legation to Canada’s quarters in Baghdad, when it attempted to pass the U.S. convoy on the road ahead and failed to respond to American troops.

The troops first tried hand signals, which didn’t cause the car to stop, CTV said, and then shot over the vehicle, and then fired two shots into the engine block and a third into the lower front windshield.

None of the four passengers or its driver were injured.

The incident happened in what’s known as the Green Zone, a heavily fortified area in the centre of Baghdad where coalition and Iraqi government offices are located.

A spokeswoman for the Foreign Affairs Department in Ottawa confirmed the incident had occurred.

Pamela Greenwell said it involved “four members of Canada’s small mission in Iraq.”

She said she could not identify who was in the car.