Oregon wildfires trigger mass evacuation

More than 40,000 people in the US state of Oregon have fled wildfires and some 500,000 have either been ordered to leave their homes or to prepare to do so, said Governor Kate Brown. The governor's latest statement seems to be dialing back previous announcements by state officials, who said half a million people have already been evacuated.

Officials say hot, dry winds sparked dozens of infernos across the state on the country's northwest Pacific coast.

"Firefighters are prioritizing life and safety as they battle a record 900,000 acres (364,000 hectares, 3,640 square kilometers) of wildfires," the state's government said in an earlier statement.

Governor Kate Brown told journalists that the exact number of fatalities was not yet known, although a news agency reported that at least four had been confirmed by local officials.

"We have never seen this amount of uncontained fires across the state," she said "This will not be a one-time event. Unfortunately, it is the bellwether of the future. We're feeling the acute impacts of climate change."

Wildfires extend to 12 states

There are currently an estimated 100 wildfires raging across 12 western US states.

One fire in Ashland, Oregon, close to the border with California, is being treated by police as possible arson.

"We have good reason to believe that there was a human element to it," Ashland Police Chief Tighe O'Meara said "We're going to pursue it as a criminal investigation until we have reason to believe that it was otherwise."

Oregon, Washington and California are the states worse affected by the blazes.

At least 10 people have died in California alone in the past two days.

In northern California's Butte County, three people were confirmed to have been killed as firefighters battled flames through the night of Thursday.

Another dozen people are reportedly unaccounted for in the area.

Strong winds have now eased off across much of the state and severe weather warnings lifted for most of California, according to the California Department of Forestry and Fire Protection.