Thousands evacuate season's biggest wildfire in northern California

A huge, fast-moving and rapidly growing wildfire in northern California has forced more than 4,000 people to evacuate as firefighters battle gusty winds and perilously dry conditions, authorities said Friday.

Fueled by a crushing heatwave, the so-called Park Fire -- the most intense wildfire to hit the state this summer -- has rapidly devoured nearly 240,000 acres (97,000 hectares) as of Friday night and is continuing to gain strength.

"This fire has been rapidly expanding 4,000 to 5,000 acres an hour," incident commander Billy See said at a press conference Friday evening.

For now it is "zero percent" controlled, despite the efforts of some 1,700 firefighters, according to state agency Cal Fire, with hundreds of additional resources ordered en route.

A total of 4,000 people have evacuated the towns of Cohasset and Forest Ranch, plus an additional 400 from the small city of Chico.

The blaze so far has destroyed 134 structures, authorities said.

Despite the structure losses, Butte County Fire Chief Garrett Sjolund said "many more have been saved."

"It is a fire that is challenging our strategies, but we are finding opportunities to deploy our resources in successful ways," Sjolund told reporters.

The fire started Wednesday near Chico, in Butte County, and within hours had devastated a wide area there and in neighboring Tehama County.

In just two days, the Park Fire has already become the 20th largest fire in California history by land area.

The blaze has generated an enormous column of dense gray smoke, with gritty clouds akin to those of a violent storm now visible in nearby US states.

Fire departments from across the state have sent crews to lend a hand.

The National Weather Service has issued a Red Flag Warning for the region through Friday night, predicting "critical" fire weather conditions.

On Thursday, police detained a 42-year-old man on suspicion of having started the fire by pushing a burning car into a ravine.

Butte County prosecutor Mike Ramsey identified the man as Ronnie Dean Stout II and said he would be held without bail until a court appearance next week.