In short:

A fire that broke out at a training area at a Canadian military base has killed at least four people.

The fire erupted late on Saturday, local time, at Canadian Forces Base Wainwright in Alberta — one of the country's busiest army bases.

Prime Minister Mark Carney said the government would be there for the victims' families "for as long as they need".

A major fire at a Canadian military base has killed at least four people and injured dozens more.

The fire erupted late on Saturday, local time, at Canadian Forces Base Wainwright in Alberta — one of the country's busiest army bases.

Fire crews scrambled as fierce winds whipped flames beyond the base and into the surrounding rural area.

An investigation into what caused the blaze is ongoing, but the Canadian military has told local news outlets that as of now there are no indications that it was a result of any terrorist activity.

Dozens of service members were rushed to hospitals across the province as the local facility was overwhelmed.

Prime Minister Mark Carney said it was one of the worst tragedies Canadian forces had experienced on domestic soil during peacetime and ordered all flags on federal buildings be flown at half-mast.

He said the violent, fast-moving fire swept through the base after breaking out at the base's training area.

"We will be there for their families for as long as they need," Mr Carney said.

"We will care for the injured through every step of their recovery, and we will stand by the women and men of the armed forces as they bear the weight of this loss.

"They will not carry it alone."

Hospitals activate 'code orange'

Mr Carney said those affected included reservists and soldiers from Princess Patricia's Canadian Light Infantry, one of Canada's most storied military regiments.

The personnel had come from bases across the country to train at Wainwright.

Cathy Keane, a mayoral candidate in Ontario, said her eldest son was among the military personnel critically injured.

"As a mother, right now I need to be with my son and family," she wrote on Facebook, saying she was travelling to Alberta.

Acute Care Alberta said several hospitals across the province had activated a "code orange", an emergency designation used when multiple severely injured patients require coordinated medical care.

The agency said emergency medical resources were stretched so thin that extremely few ambulances were available in the Edmonton area.

It urged people to avoid the University of Alberta Hospital emergency department if possible.

Wainwright Mayor Bruce Pugh said the town's small hospital was not designed to handle a mass-casualty incident but praised the response of local medical personnel.

He said helicopters and planes transported patients to other facilities for treatment.

At least 10 ambulances were parked in and around the Wainwright health centre late on Saturday as paramedics and soldiers rushed about.

One patient was seen being loaded into an ambulance.

The town of Wainwright, near the base, has about 7,000 residents.

ABC/AP