About 3,600 people have been told to leave their homes as an out-of-control wildfire continues to expand in central B.C.

The fire is about 400 kilometres northeast of Vancouver, and was sparked Thursday near a forest service road. It was just two hectares in size at 3 p.m. on Thursday and had expanded to 1,500 hectares by 3 p.m. Friday.

Around 120 firefighters from the B.C. Wildfire Service, 15 pieces of heavy equipment, six helicopters and crews with local fire departments are involved in fighting the fire.

Around 3 p.m. on Friday, Cariboo Regional District upgraded an evacuation alert to an order for an estimated 2,050 properties in an area west of Highway 97 spanning from the northern boundary of 100 Mile House to the northern tip of Lac La Hache.

That order includes the majority of homes in the communities of 105 Mile House and 108 Mile Ranch.

Another 607 properties in Lac La Hache were placed on alert.

"By acting now we save the issue of smoke and congestion and confusion," said Al Richmond, chairman of the regional district.

"Given the logistics ... we need to start now and secure the community and see that people are safe so that we're not doing this later in the evening."

He said the decision to evacuate was made as the wind began to pick up in the area of the blaze, and firefighters warned that smoke and flames could begin spreading aggressively.

2 evacuation centres opened

Some of the evacuated homes in Lac La Hache have only one way out in case of a major fire, and a valley near the community could quickly funnel the fire toward homes if the wind pushes the blaze farther northwest.

"The fire activity is so unpredictable, we need to move people out of any potential path it has, and that's a very logical path for it to take," said Richmond.

Mounties were going door-to-door Friday afternoon, telling residents they needed to leave. Evacuees will be able to drive to safety.

"We just stress for folks to remain calm and follow the instructions they're given when they get to the edge of the community. People will be there to direct traffic," Richmond said.

Two emergency centres for evacuees have been opened at 100 Mile House's curling rink and at the Ramada Inn in Williams Lake.

Insane <a href="https://twitter.com/hashtag/wildfire?src=hash">#wildfire</a> outside <a href="https://twitter.com/hashtag/100milehouse?src=hash">#100milehouse</a> in BC <a href="https://twitter.com/hashtag/canada?src=hash">#canada</a>. one of the strangest things I've seen! <a href="https://twitter.com/hashtag/cariboo?src=hash">#cariboo</a> <a href="https://twitter.com/hashtag/forestfire?src=hash">#forestfire</a> <a href="https://twitter.com/hashtag/fire?src=hash">#fire</a> <a href="https://twitter.com/hashtag/paddleboarding?src=hash">#paddleboarding</a> <a href="https://t.co/WtLSpgdpyf">pic.twitter.com/WtLSpgdpyf</a> —@CNLastro

Richmond urged all of those evacuated to turn off the gas and electrical outlets at their houses before they leave, if possible, and to register so their families know they're safe.

Temporary accommodations are also being arranged at high schools in Williams Lake and 100 Mile House.

No reports of any property damage

The blaze began within a few kilometres of two sawmills, both major employers for the region, according to Richmond. Luckily, the wind so far has blown the flames away from those structures and more densely populated areas.

The local fire department has placed sprinkler protection units at many of the properties evacuated on Thursday to keep the structures wet and prevent them from catching fire.

But there's no word if there has been any property damage since the fire expanded on Friday.

"Today we've been focusing on people's safety. The Cariboo Fire Centre will get us that information as they can, but their crews are focused on trying to direct this fire and slow it down if they can," said Richmond.

Strong winds are making it harder to contain the wildfire and raising concerns that people will be affected by the smoke. (B.C. Wildfire Service)

It's believed the fire was caused by human activity, and high winds have helped the flames to spread rapidly through the thick forest in the area.

On Friday, the winds continued to vary in both strength and direction, with the weekend's weather forecast not showing much potential for rain.

"We're going to be significantly moving resources [here] the next few days," said Kevin Skrepnek, B.C.'s chief fire information officer.

He urged people in the area to stay tuned to local radio for the latest news on the fire and evacuation orders, while warning that it might be days before people could return to their homes.

"Given the size of the fire that they're dealing with, this is going to be not just a temporary move."