In account of Saturday’s events, Rutland told reporters that members of the infantry had been conducting “high-intensity combat training with live munitions” at a grenade range and attack range.

He told reporters that officials knew about the fire on the base for several hours, but it was decided that training “could carry on for a certain amount of time”.

“I spoke to my commander last night, and he said within 30 seconds to a minute they saw no fire, and then there was a fire right on top of them,” Rutland said.

Rutland said it was not yet known what exactly caused the fire.

Some witnesses had said they had heard explosions, fuelling speculation that oil and gas infrastructure may have been hit and sparked the fire. But Rutland said authorities “do not believe this [incident] to be a result of any oil and gas infrastructure”.

The Canadian Armed Forces has said that “while the incident remains under investigation, at this time, there are no indications that it was the result of any terrorist activity”.

Forecasters had issued a wind warning on Saturday for large parts of Alberta, predicting wind gusts of up to 90km/h (66mph), Canadian broadcaster CBS said.

According to Rutland, the investigation may take at least a month.

Wainwright, about 130 miles east of Edmonton, Alberta’s capital, is one of the main bases used by the Canadian military for live-fire training exercises, and it houses troops from Canada and allied countries.

About 690 military personnel and 300 civilian workers are on site on a typical day.