A Canadian Air Forces officer was in direct command of two American pilots who bombed Canadian troops in Afghanistan last April in a so-called friendly fire incident, according to a published report.

The Ottawa Citizen reported Sunday that an unnamed Canadian major, assigned to the U.S. Airborne Warning and Control System (AWACS) under a NATO exchange program, was serving as mission crew commander the night of April 17, 2002. Four Canadian soldiers were killed and eight injured that night, when two F16s bombed Canadian troops engaged in a live-fire training exercise south of Kandahar.

The Canadian was the senior officer for the crew of air controllers on the AWACS plane, which acted as a go-between for the American pilots and the Coalition Air Operations Command headquarters on the ground. According to the Citizen report, he was the first to deny permission to Maj. Harry Schmidt and Maj. William Umbach, the two F16 pilots, to fire on what they believed was anti-aircraft fire.

According to transcripts of communications the night of the incident, which were released in July, Schmidt requested permission to fire his 20-mm machine gun when he encountered the Canadians' artillery flashes. The Canadian controller relayed the request to the command centre but was told to deny it. Another controller told Schmidt to hold fire pending more details.

After seeing more artillery fire, Schmidt declared he was firing in self-defence, a call AWACS cannot override. Four seconds later, the Canadian controller relayed that information to the ground and was told, 38 seconds later, "Be advised Kandahar has friendlies. You are to get (the F16s) out of there as soon as possible."

By that point, the pilots had already dropped a 225-kg bomb on the Canadian soldiers below.

The two U.S. pilots each face up to 64 years in prison on charges of involuntary manslaughter, assault and dereliction of duty. Their lawyers are expected to call the Canadian controller to testify at upcoming Article 32 hearings that will determine whether the evidence is sufficient to proceed to general courts martial. He has already testified at both the U.S. and Canadian boards of inquiry that probed the incident.

The Canadian officer told the U.S. board that he did not review the daily written airspace instructions, relying on the command centre to pass on information. The controller's commanding officer, Lt.-Col. Martin Galvin of the 552nd Air Control Wing -- Canadian Component, told the Citizen that the officer would not have received any special information about the training exercises that wasn't also known to the U.S. controllers.

"He was in the loop, but nationality made no difference to the decisions that were made," Galvin said. "It was a coincidence that he was Canadian."

Galvin said the officer is devastated over the accident.