One of the largest cities in Canada's far north is being evacuated amid warnings that a wildfire could reach it by the weekend.

The 20,000 residents of Yellowknife, the capital of the Northwest Territories, have been given until noon Friday (18:00 GMT) to leave.

As of late Wednesday, the fire was within 17km (11 miles) of the city.

Another fire is threatening the community of Hay River.

One evacuee told the CBC her car began melting as she and her family drove through embers while fleeing the town.

The Northwest Territories declared a state of emergency late on Tuesday as it battles more than 200 wildfires.

Shane Thompson, the region's environment minister, told a press conference on Wednesday that the fires had "taken another turn for the worse" and now represented a "real threat" to Yellowknife.

"I want to stress that the city is not in immediate danger," he said. "[But] without rain, it is possible [the fire] will reach the city outskirts by the weekend."

"You put yourself and others at risk if you choose to stay."

Hay River Mayor Kandis Jameson estimated that about 500 people were still in the community of some 3,500 people as of Tuesday despite an evacuation notice issued for the town over the weekend.

The fire moved 30km in a few hours because of strong winds earlier this week, closing the only two highways out of the town.

The road out of Hay River is "treacherous", the mayor said, and food and petrol supplies are getting low in the town.

Phone and internet services have also been down in the remote region.

Resident Lisa Mundy described how her bumper had begun to melt, her windscreen had cracked and her car had filled with smoke as she and her husband left the town with their two children on Sunday.

"You couldn't see anything — we were driving through embers," she said.

"[My six-year-old son] actually said to me, 'I don't want to die, mommy,' and he kept saying it so many times."

Canada's military has been co-ordinating airlift operations out of several communities in Northwest Territories' South Slave Region that have been threatened by wildfires in recent days.

It is the largest airlift evacuation effort in the territory's history.

Most evacuees have been brought south to the neighbouring province of Alberta, with no indication as to when they will be able to return home.

Fort Smith, K'atl'odeeche First Nation, Hay River, Enterprise and Jean Marie River are all under evacuation orders.

Enterprise, home to 120 people, is "90% gone" after a wildfire swept through this week, the community's mayor told the CBC on Tuesday.

Canada is having its worst wildfire season on record, with nearly 1,100 active fires burning across the country as of Wednesday.

Experts have pointed to a warmer and drier spring than normal as the reason.

Scientists say climate change increases the risk of the hot, dry weather that is likely to fuel wildfires.