Wildfires near Spokane destroy more than 700 buildings, force 64,000 to flee

Aug 3 (Reuters) - Wildfires raging on the outskirts of Spokane, Washington, for a third day have destroyed at least 700 buildings and forced tens of thousands of people to flee their homes in and around the state's second-most populous city, officials said on Monday.

The cluster of three blazes ranks as the top firefighting priority in the U.S. as a whole, including the drought-parched Pacific Northwest, where dozens of major wildfires have been burning for weeks, degrading air quality across a wide region.

The Spokane-area fires have scorched more than 8,000 acres since erupting on Saturday in and around suburbs on the northern fringe of the city, home to about 230,000 residents west of the Rocky Mountain foothills near the Idaho border.

As of Monday, some 64,000 people were under immediate evacuation orders, up from 4,000 a day earlier, according to Benjamin Cossel, a spokesperson for the incident command center.

At least 700 structures have gone up in flames, most of them in residential areas, and aerial infrared surveys showed that possibly another 400 buildings, including homes, had been damaged or destroyed, Cossel said.

The cause of the blazes was under investigation.

No injuries or fatalities have been reported so far, he said, adding, "There's a high probability that will change in the coming days" as flames subside and search teams are able to reach devastated communities still inaccessible due to extreme fire activity.

An unspecified number of people have been reported missing as flames spread out of wooded areas into neighborhoods and commercially developed areas, "turning from a wildfire to an urban conflagration," he said.

Roughly 1,100 firefighters were battling the Spokane blazes as of Monday, Cossel said, a fraction of the more than 29,200 personnel assigned to wildfires nationwide, most heavily concentrated in Oregon, Washington state and Idaho, according to the National Interagency Fire Center in Boise.

"The worst thing in the world is to let people go home only to have to evacuate them again 24 to 48 hours later," Cossel said.

As of Monday, firefighters had yet to contain any of the three Spokane-area blazes, officials said.