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 agency reported more than 100 large new wildfires on Sunday across 15 states, the bulk of them in the Northwest, stretching resources thin across the region.
'EXPLOSIVE' FIRE BEHAVIOR
North of the U.S.-Canadian border, flames continued to rage across British Columbia, where record drought conditions have led to what officials over the weekend called "explosive" fire behavior in the southern part of that province.
Aerial firefighting assets in Spokane were so far limited to four fixed-wing tanker aircraft, with no water-dropping helicopters currently available, Cossel said.
Fire managers hoped their crews could make greater headway during a narrow window of cooler, less windy weather expected to prevail on Monday and Tuesday, before extremely high temperatures, low humidity and gusty conditions are forecast to return at midweek, Cossel said.
Even though fire activity in some spots has eased in comparison with Sunday, authorities were reluctant to lift evacuations in most of the fire zone.
"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.
The Interagency Fire Center has documented a total of 44,722 wildfires year to date nationwide, the highest number for this time of the year in at least a decade, with nearly 5.2 million acres consumed, the most from January to early August since 2022.
The conditions driving the increase in wildfire activity in North America, Europe and elsewhere in recent years, especially periods of prolonged drought and extreme heat, are largely a function of human-caused climate change, according to scientists.
(Reporting by Steve Gorman in Los Angeles, editing by Deepa Babington)
