Massive Canada wildfire spreads south forcing more evacuations

A massive wildfire in Alberta has grown to 850 square kilometres (328.2 sq miles), with thousands of people facing their second evacuation in three days.

The blaze has grown five times its initial size as it spreads south, prompting more than 88,000 evacuations.

But 25,000 of those people who left their homes on Tuesday and moved north may now have to be resettled again.

"Our focus right now is on getting those people south as quickly as possible," said the Alberta premier.

The fire is growing in size due to high winds but it is "under control", said Rachel Notley.

Urban areas in the south are better able to support the displaced, officials said.

The fire started on Sunday in Canada's oil sands region and many oil sands projects have cut production.

There are still no known casualties from the fire but there was at least one vehicle crash with fatalities on the evacuation route.

More than 88,000 have fled Fort McMurray

Scott Long of the Alberta Emergency Management Agency called the blaze "an extreme fire event" and that rain would be needed to fight it.

Cooler temperatures and rain are forecast, giving hope that it could become easier to contain the fire.

Wildfires in numbers

• 49 wildfires in total

• seven are 'out of control'

• more than 1,100 firefighters

• 145 helicopters

• 138 pieces of heavy equipment

• 22 air tankers

The fire has knocked out nearly a third of the country's daily crude capacity.

At least 64,000 barrels of crude output is offline as a result of the fire, according to Reuters.

'It's catastrophic' says fleeing resident

"The smoke was really overpowering. It was a terrifying experience," says Szymon Bicz, who fled his home.

"Thick black smoke was closing in and surrounded the car. People were driving up on paths and grass verges just to get out of there. I'm hoping my rented house is still intact but I just don't know.

"The whole region is at risk. It's absolutely catastrophic."

'It just doesn't seem real': Fort McMurray residents flee their homes

Residents north of Fort McMurray are being told to shelter in place.

The blaze grew close to the local airport on Thursday, with the CBC reporting that some buildings have been destroyed, but the main terminal is still intact. All flights are cancelled.

"It is a possibility that we may lose a large portion of the town," Scott Long, an official with Alberta's emergency management agency told Reuters.

Residents of Fort McMurray took shelter in gymnasiums, arenas and hockey rinks

Thousands have stayed in arenas, hockey rinks and school gymnasiums, some with little food and other resources.

Authorities in Alberta have called the fire "catastrophic".

Prime Minister Justin Trudeau said on Thursday that the federal government will match donations to the Canadian Red Cross to assist those affected by the fire.

"The outpouring of good will and compassion from Canadians right across the country has not only been inspirational, it has been entirely characteristic of who we are and the fundamental human values we share as Canadians," Mr Trudeau said.