The Canadian government announced the state of emergency on Wednesday as wildfires continued to rage through the northern city of Fort McMurray, in the western province of Alberta, displacing tens of thousands of people.

The entire population of the city in the center of Canada's oil sands region - around 88,000 residents - has been evacuated. Strong winds are threatening to spread the blaze, which has already incinerated more than 1,500 structures and could destroy much of the city. The evacuation is the largest in the province's history.

Nine air tankers, a dozen helicopters and around 250 firefighters were battling the flames, and the military has been put on alert.

"Obviously, Fort McMurray being evacuated has been extremely difficult, not just for the province and officials, but for the folks who live there," said Prime Minister Justin Trudeau.

Trudeau added that he had offered Alberta Premier Rachel Notley "our total support as a government to anything needed in the short-term but obviously anything in the long-term."

Shows of solidarity

Meanwhile, evacuees clogged highways and filled up work camps operated by local energy companies. Nearby residents used Twitter to offer shelter, supplies and food to the displaced.

Tens of thousands of people have left Fort McMurray, the largest evacuation in Alberta's history

As emergency workers from other parts of the country flew in to help with the crisis, the fire threatened to spread to neighborhoods on the other side of the river from where it originated.

Firefighters told reporters they expected the fire to gain strength as the day moves forward. There is still no end in sight to the wildfires, which have yet to claim any casualties, the local fire chief said.

The fire has been blamed on unseasonably hot temperatures and dry conditions in much of Alberta.

This is the second major fire around the city in less than a year. Last May, wildfires in the area led to the evacuation of hundreds of workers from Canada's energy heartland.

blc/cmk (Reuters, dpa)