At least 10 dead in California wildfires

At least 10 people were killed and 100 injured in wildfires whipped by powerful winds that swept through California wine country on Monday. At least 1,500 homes and businesses were destroyed, while thousands of people fled to safety through smoke and flames.

The fires broke out overnight and flames reached high-end resorts, grocery stores and tree-lined neighbourhoods. Two hospitals in Santa Rosa, the largest city in the region with 175,000 people, were forced to evacuate patients.

The state's fire chief said the fires were burning throughout an eight-county swath of Northern California, including Napa, Sonoma and Yuba counties.

This aerial photo provided by the California Highway Patrolshows some of hundreds of homes destroyed in a wind-driven wildfire that swept through Santa Rosa. California Highway Patrol Golden Gate Division via AP

Long lines formed at gas stations when many families heeded a middle-of-the-night call to get out. A representative of Pacific Gas & Electric said 114,000 customers were without power.

"It was an inferno like you've never seen before," said Marian Williams, who caravanned with neighbours before dawn as one of the wildfires reached the vineyards and ridges at her small Sonoma County town of Kenwood.

Ms Williams could feel the heat of the fire through the car as she fled. "Trees were on fire like torches," she said.

With downed trees or flames blocking routes, Sonoma County residents struggled to figure out what roads to take.

"Imagine a wind-whipped fire burning at explosive rates. This is 50 miles per hour. Literally it's burning into the city of Santa Rosa … burning box stores," said California Department of Forestry and Fire Protection Director Ken Pimlott. "This is traditionally California's worst time for fires."

Napa County Fire Chief Barry Biermann said the fires had burnt more than 176 square kilometres. Crews had not yet been able to contain a fire heading toward downtown Napa.

"Right now, with these conditions, we can't get ahead of this fire and do anything about the forward progress," Mr Biermann said.

Gov Jerry Brown declared a state of emergency in Napa, Sonoma and Yuba counties. Smoke was thick as far away as San Francisco, 96 kilometres south of the Sonoma County fire.

John Dean was driving to his Sonoma County home early on Monday when he saw a house on fire along the road. Soon he saw more houses engulfed in flames.

"I mean blazing, falling down on fire," he said.

Mr Dean sped to his home in Kenwood, alerted neighbours and fled to the town of Sonoma. He was one of hundreds of evacuees who streamed into a 24-hour Safeway market overnight, while authorities set up an official evacuation centre.

Wildfire torches homes in southern California

Maureen McGowan was housesitting for her brother near Kenwood, and said both of the homes on his property were on fire when she left. At the Safeway, she pointed to her feet, still in slippers. She had fled so fast that she hadn't put on her shoes.

Belia Ramos, chairwoman of the Napa County Board of Supervisors, said "tremendous" wind gusts were making the fire unpredictable. "It's something that we're having to be very cautious about."

"We're focusing on making evacuations and trying to keep people safe. We are not prepared to start counting," she said shortly after sunrise.

Ann Dubay, a spokeswoman for the Sonoma County Emergency Operations Centre, said the area where the largest fire started was relatively rural but the flames "went through many, many neighbourhoods", and authorities did not know how many structures were gone.

Emergency lines were inundated with callers reporting smoke, prompting officials to ask that the public "only use 911 if they see actual unattended flames, or are having another emergency".

Business owner Andy Lahiji stood before a burnt-out warehouse where he said he had lost his inventory of furniture and other property. He said it took fire trucks ages to arrive Monday morning.

"They said, 'We have so many other places to go, you have to wait.' And then when they came, they had only a couple of guys," he told the station. "I feel very sad. I'm glad nobody got hurt. Hopefully insurance takes care of it."