Four service members are confirmed to have died, while a further 39 people are in hospital – 19 of whom are in critical condition.

Officials identified the deceased as Sgt Morgan Wong, Pte Shaun Farrell, Private Aidan Goulding and Pte Hayden Lykkemark.

Officials have not indicated whether or not the government expects the death toll to rise but said many people had suffered severe burns.

On Saturday evening, Royal Alexandra Hospital in Edmonton declared a code orange – a disaster response protocol for a high-casualty incident. It was stood down on Sunday afternoon.

Alberta’s health service said the emergency response lasted for 10 hours, and involved 22 ambulances and eight aircraft.

Ongoing care for the injured is expected to be “intensive”, a statement continued.

A stream of ambulances were seen arriving at the hospital and one doctor told Canadian public broadcaster CBC that the facility had been “completely overwhelmed” by the number of patients.

Brandon Simmons, a hospital resident receiving long-term care at the nearby Wainwright Health Centre, witnessed the aftermath of the fire.

He said he remembered seeing people with burns, while one person had their clothes “blown off” and was wearing only underwear.

In response to the incident, Minister of National Defence David McGuinty said: “Albertans are lining up to give blood.”