Scorched trees stand near Opal, Alta., about 60 kilometres northeast of Edmonton, on Friday. (John Ulan/Canadian Press)Residents of a rural area north of Edmonton were told to leave their homes on Sunday as winds shifted, causing an out of control brush fire to spread.

Officials said winds gusting up to 40 km/h caused the flames to jump a 10-metre-wide fireguard, burning an area bordering on Westlock County and the County of Thorhild.

A number of families living near the fire were told to leave. Officials said their homes were not believed to be in imminent danger and the evacuation was a precaution.

Officials had said Sunday and Monday would be their toughest days yet, with high winds and high temperatures in the forecast.

Officials said they haven't been able to get an accurate reading on the size of the blaze near Opal, Alta., because the smoke is too thick for them to map it from the air.

As of Friday, it had burned at least 22 square kilometres. The blaze has destroyed one home, but there have been no injuries.

Officials say sprinklers will be set at nearby homes, and fire engines and water tenders will stay close to structures at risk.

Water bombers are being used to attack the flames and fireguards are being dug to keep the fire away from homes and outbuildings.

Volunteers lend hand

Sturgeon County firefighters douse a flare-up Friday on the site where a home was lost Thursday to the brush fire burning near Opal, Alta. (John Ulan/Canadian Press)About 170 firefighters from Alberta Sustainable Resource Development are on the fire lines.

In addition, dozens of volunteer firefighters from neighbouring communities are helping battle the blaze.

Charles Newall, the reeve of Thorhild County, has abandoned seeding his grain fields in order to volunteer — a sacrifice he says will likely double the time it takes to get his crop in.

"In rural communities, you have to rely on one another … because nobody else is going to help you. You have to help yourself," he said.

In all, about 60 volunteer firefighters have offered to help since Wednesday, putting their own work on hold.

Deputy reeve and businessman Kevin Grumetza has been volunteering for 20 years.

"It makes a really bad situation a whole lot better when … everybody comes out to help support the situation and try to get this thing resolved," he said.

County chief Nick Kuzyk has been operating on just a few hours of sleep a night, also neglecting his farm and trucking business.

But Kuzyk, whose family property was damaged when he was a young boy because there was no rural fire department to save it, wouldn't dream of being anywhere else.

"I always said to myself the day that they ever have a fire department, that I would join as soon as I could," he said. "And I joined the fire department when I was 18 and now I'm 45 and I've been here ever since."

Officials said it could take several weeks to completely extinguish the fire.

With files from The Canadian Press