KELOWNA, B.C. - The number of B.C. Okanagan residents forced to flee their homes was getting larger Sunday as a wind-whipped wildfire raged on the doorstep of a densely populated Kelowna subdivision.

Officials giving the day's first briefing said there had been about 17,000 people evacuated from 6,500 homes.

Among them was Doug Findlater, the mayor of West Kelowna, who said he and his family have registered with the emergency centre but was forced to admit he had no idea what shape their house was in.

Officials said nine structures had been destroyed so far, at least three of them houses, but were able to offer no other details.

Residents were asked to turn off their sprinklers and automated watering systems to conserve water for the firefighters.

It's also not clear what caused the blaze, though Assistant Fire Chief Lou Wilde hinted strongly it may have been human-caused.

"I'm quite certain lightning wasn't a factor," Wilde said. "It's brutal conditions to work in this heat."

Among the evacuated were residents of a care home, who were moved to another facility.

The fire in West Kelowna had burned three square kilometres by midnight Saturday night and a spokeswoman for the B.C. forest fire service couldn't predict when the blaze might be brought be under control.

Firefighters from all the surrounding cities in the Okanagan, including Summerland and Peachland, were helping in the efforts, while the RCMP also bumped up its contingent.

RCMP Cpl. Dan Moskaluk said there were between 40 and 45 RCMP officers working on the fire to ward off looters, among other things.

"Our mandate is to secure evacuated areas and give some peace of mind to people who have been evacuated from those homes," Moskaluk said.

Officers were also advising boaters on Okanagan Lake to stay out of the area. Too many of them were crowding near the shore to get a look at the fire Saturday, he added.

Power was out in certain areas of the evacuated subdivision, and also in Peachland and parts of Summerland.

A second fire was burning at the nearby Rose Valley Reservoir, where another 1,500 homes were under evacuation alert.

The fire whipped up late Saturday afternoon, growing exponentially as it was fed by fierce winds.

The winds died down somewhat overnight and cooler temperatures were predicted for Sunday, but Elise Riedlinger, a spokeswoman for the B.C. forest fire service, said it was impossible to say when crews might finally win the upper hand.

"They're definitely going to be working as hard as they can," Riedlinger said.

Forests Minister Pat Bell said the fire has the potential to be worse than the firestorm that devastated the city in 2003.

"I don't think you can compare it to 2003 at all. In 2003, you were in a very rural area, the homes were spread out. In the Glenrosa subdivision, much of it is much like any subdivision in British Columbia with smaller lots that are closer together," Bell said in an interview.

"This fire has the potential to be very volatile. If we see any sort of substantive winds, it can turn around and come up behind you and you will have no way out. So the best decision that anyone can make at this point, if you're in the evacuation area, is to get out."

In 2003, lightning strikes triggered a fire that scorched 250 square kilometres, destroyed more than 200 homes and caused millions of dollars in property damage.

Hotels in Kelowna and the surrounding area were fully booked.

The large Gorman Brothers sawmill, with stacks of stored lumber, was also threatened and the local Holiday Inn was evacuated.

"The wind is so bad, you know," said Bettyann Barton, who lives several kilometres from the fire.

"You just don't know where it's going to go. . .Very scary, very scary."