KANDAHAR — The Canadian military has confirmed that hostile fire forced down a Chinook helicopter in August, but remains uncertain about what weapon the insurgents used.

Initial reports from Task Force Kandahar suggested the helicopter, which was carrying 21 people including crew, had taken small-arms fire as it flew over the Panjwaii district.

Eight people suffered minor injuries when the Chinook was forced to make an emergency landing near the village of Armarah, southwest of Kandahar city.

But a recently completed investigation by military officials in Afghanistan revisited that conclusion, according to the commanding officer of the Canadian air wing in Kandahar.

"What we know is that it was taken down by enemy action, nothing has changed there," Col. Paul Prevost said.

"What we cannot find out exactly is the weapon that was used on it. You have to understand the airplane was burned within the following minutes."

Following the release of several thousand pages of classified documents about the war on the website Wikileaks, there had been speculation the Taliban was making use of heat-seeking missiles.

A Canadian was killed with six others in 2007 while aboard an American Chinook that was struck with what witnesses described as a shoulder-launched surface-to-air missile.

During the Soviet occupation of the 1980s, the country was awash with Stinger missiles supplied by American intelligence to mujahedeen commanders.

But Prevost said there were no indication that anything more sophisticated than small-arms fire brought down the helicopter. The air wing has not revised the threats faced by its aircraft.

"They use very rudimentary weapons," Prevost said. "All things they try to use against ground forces they try to shoot at airplanes."

The conclusions of the report are based on witnesses testimony as the helicopter was completely charred by the fire that broke out after being hit.

Prevost praised the crew of five, who were able to land safely and evacuate the aircraft quickly.

"Their good training, good techniques saved the lives of 21 people," he said.

The report has been sent to Ottawa, along with a letter signed the air wing's command endorsing its findings.

It's not the first time a Canadian helicopter has crashed in Afghanistan.

On July 6, 2009, Master Cpl. Pat Audet, 38, of Montreal, and Cpl. Martin Joannette, 25, of St-Calixte, Que., died in Zabul province when their Griffon CH-146 helicopter crashed on takeoff. Three other Canadian Forces members were injured, one of them seriously. A British officer was also killed in the crash.

Last year's crash was believed to have occurred when the chopper clipped a security wall while trying to manoeuvre in a blinding cloud of dust.

Canada now has five Chinook helicopters remaining in its Afghanistan fleet.

It purchased six from the United States a couple of years ago at a price tag of $292 million. The military says they have done yeoman's service since they began flying in Afghanistan early last year.