'Firenado' rips through California in year's biggest blaze

A rare fire tornado has ripped through bushland in northern California, as the state's largest wildfire this year doubled in size overnight and burned out of control.

The Park fire, which started on Wednesday, has already burned through more than 164,000 acres of land northeast of Chico, and was 3% contained on Friday, Cal Fire said.

A 42-year-old man was arrested on Thursday on suspicion of starting the blaze by rolling a burning car into a gully near Alligator Hole in Butte County.

Footage obtained by BBC News shows the "firenado" - a swirling vortex of flames and ash formed in intense heat and high winds - twisting through an area in Butte County.

The blaze has forced mandatory evacuations in Butte, where California deadliest wildfire, the Camp Fire, killed more than 80 people in 2018.

The 400-strong population of Cohasset have already been moved as the fire burns largely out of control.

"Evacuations are ongoing as the fire grows," said Megan McCann, of Butte County Sheriff's Office on Thursday. "We had assistance from 10 different law enforcement and fire agencies. More are on the way.

Cal Fire said that 34 structures had been destroyed, while 4,200 remain threatened.

The Park fire has grown exponentially since it sparked on Wednesday, growing from about 1,400 acres on Wednesday near Chico, California, spreading about 45,500 acres by Thursday into California's Central Valley, before tripling in size by Friday.

The National Weather Service issued a red flag warning for northern Sacramento Valley, and warned high winds and low humidity on Friday could combine to "cause new fire starts and ongoing wildfires to ... grow rapidly and dangerously in size and intensity".

The LA Times reported that the fire was threatening to engulf the Ishi Wilderness and Lassen foothills - areas untouched by fire in almost a century and therefore filled with a large amount of fuel for the blaze.

The biggest current blaze in the US, however, was across the border in Oregon, where the Durkee fire has burned at least 240,000 acres, threatened multiple small towns, scorched ranch land and killed cattle by the hundreds.

Canada is also battling large wildfires, one of which has destroyed up to half of the historic town of Jasper in Alberta, and large areas of the Jasper National Park. Rain on Friday aided the hundreds of firefighters called in to battle the blaze.