A soldier testifying during a court martial about a deadly explosion in an Afghanistan training range refused to blame his commanding officer, who is accused of manslaughter.

Canadian Forces Master Cpl. William Pylypow testified Tuesday morning in Calgary about the 2010 blast, which left him injured.

"It's a war zone. It's not intentional. I don't know what the circumstances are, I don't know if I want it classified as an accident, but it is combat so it's unfortunate. I don't want that to happen, but blame is outside that," he told reporters.

Reservist Maj. Darryl Watts is accused of playing a role in the death of fellow soldier Cpl. Joshua Baker, 24, at a training range just north of Kandahar city in February 2010. He pleaded not guilty to six charges, including manslaughter.

Four other soldiers were also wounded. Watts, who was a captain at the time, was the officer in charge on the day of the accident.

Pylypow has fully recovered from his injuries. He described Watts as always well prepared – a captain who cared about everyone under his command. He recalled the deadly blast, which saw a Claymore explosive (C19) packed with 700 steel balls hit his platoon.

"You felt the air wave hit your face and then my arm got hit and got spun around, so I thought I had lost my arm, to be honest with you, because everything was numb and it was pinned behind my kit," he said. "When my logic came back, yes, I thought it was Taliban."

Defence lawyer Balfour Der said Watts wasn't responsible for the incident.

"What we heard from today were people who were involved in firing on the C19 – the explosive device that malfunctioned here. And they all, to a man, made it clear that it was not Maj. Watts who was in charge, who was responsible for anything that was going on there."

But prosecutor Maj. Anthony Tamburro disagreed. "There was a lack of control on that range and it seems that some people were not behind cover and in fact some people were walking about willy-nilly."

Possible prison time

Watts' court martial is similar to regular court proceedings, except that the judge is a senior military officer and the jury is made up of five other officers who will determine his guilt or innocence.

If convicted, Watts could be sentenced to prison time in the Canadian Force's detention barracks in Edmonton or in a regular correctional facility.

Lesser punishments can include dismissal from the military, a reduction in rank or a fine. Two other Canadian Forces personnel were charged following the incident.

Warrant Officer Paul Ravensdale, who was the safety officer at the firing range, faces identical charges to Watts. Last September, Maj. Christopher Lunney pleaded guilty to negligent performance of duty while four other charges were dropped. He was demoted to captain and received a severe reprimand.