Four Canadian Armed Forces members died and 39 were injured when a fire swept through a training area at Canadian Forces Base Wainwright in Alberta, officials said, in what the prime minister called one of the worst peacetime tragedies for the military on Canadian soil.

The fire ignited at about 4:00pm local time on Saturday, 17 October, in the base's training area, according to the Department of National Defence. High winds drove it rapidly beyond the training area and towards the range administrative area, the military said.

Prime Minister Mark Carney said in an address from Ottawa on Sunday that four service members had lost their lives and that dozens more were seriously injured. 'This is one of the worst tragedies the Canadian Armed Forces have experienced on Canadian soil in peacetime,' he said.

The military named the dead as Sergeant Morgan Wong, of the Loyal Edmonton Regiment serving with 3rd Battalion, Princess Patricia's Canadian Light Infantry, and Privates Shaun Farrell, Aidan Goulding and Hayden Lykkemark, all of the same battalion. Flags were ordered flown at half-mast.

Alberta Premier Danielle Smith said at a briefing that 39 injured people were being cared for in hospital and that at least 19 were in critical condition. Health authorities deployed 30 units to Wainwright, including 22 ground ambulances and air ambulance crews from Edmonton, Saskatoon and Calgary; patients were moved to hospitals in Edmonton, Red Deer and Calgary.

Major-General Wade Rutland said soldiers were conducting live-fire training with grenades, a grenade launcher, small arms and ammunition when a grass fire started about a kilometre away and spread quickly in 'uncommonly strong winds'. He said the cause was under investigation and that an inquiry was expected to take at least a month.

Defence officials said there was no indication of terrorist activity, oil and gas infrastructure or outside interference. Wainwright, about 210km east of Edmonton, is one of Canada's busiest military training bases and normally hosts about 690 military personnel and 300 civilian workers.

The fire disrupted advance voting ahead of a provincial vote on whether to begin the process towards a possible referendum on Alberta's secession from Canada.