Firefighters in California on Saturday battled raging blazes at both ends of the state that have left at least nine people dead and thousands of homes destroyed, but there was little hope of containing the flames anytime soon.

More than 250,000 people have been ordered to evacuate a wide area near the state capital Sacramento and, in southern California, the Hollywood resort town of Malibu.

So far, all nine fatalities were reported in the town of Paradise, in Butte County, where more than 6,700 buildings -- most of them residences -- have been consumed by the late-season inferno, which is now California's most destructive fire on record.

From miles around, acrid smoke could be seen in the sky around Paradise, the sun barely visible. On the ground, cars were reduced to metal carcasses, while power lines were also gnawed by the flames.

Locals fled the danger, but police told AFP some farmers returned to check on their cattle.

"The magnitude of destruction we have seen is really unbelievable and heartbreaking, and our hearts go to everybody who has been affected by this," said Mark Ghilarducci, the director of the California Office of Emergency Services.

Governor-elect Gavin Newsom declared a state of emergency to provide assistance to the hardest-hit areas in the fire-prone state.

The fast-moving blaze in the north, which authorities have named the "Camp Fire," broke out early Thursday.

Fanned by strong winds, it has so far scorched 100,000 acres (40,500 hectares) and is 20 percent contained, the California Department of Forestry and Fire Protection (Cal Fire) said Saturday. So far, three of the more than 3,200 firefighters deployed have been injured.

They estimate they will need three weeks to fully contain the blaze.

Butte County Sheriff Korey Honea said four people were found dead inside a vehicle in the Paradise area, while another was found nearby. Three more were found outside a residence, and one inside a house. Dozens of other people were reported missing.

Local power authorities have told state officials an outage occurred near the spot where the fire erupted, The Sacramento Bee reported, but there is still no official cause of the Camp blaze.

President Donald Trump, who was in France for World War I commemorations, drew criticism online for his somewhat unsympathetic reaction to the devastation.

"There is no reason for these massive, deadly and costly forest fires in California except that forest management is so poor," Trump tweeted Saturday.

"Billions of dollars are given each year, with so many lives lost, all because of gross mismanagement of the forests. Remedy now, or no more Fed payments!"

- Malibu mansions in flames -

In southern California, more wildfires burned, including one just north of Los Angeles and another in Ventura County near Thousand Oaks, where a Marine Corps veteran shot dead 12 people in a country music bar on Wednesday.

Authorities said some 200,000 people are under mandatory evacuation orders, including the entire city of Malibu.

The "Woolsey Fire" had consumed around 69,000 acres, destroyed at least 150 homes and was so far not contained, the Ventura County Fire Department said, adding that evacuation orders were issued for some 88,000 homes in the county and neighboring Los Angeles County.

"We heard this was coming so we set up the sprinklers and we hosed the whole house down," said Malibu resident Patrick Henry. "We pretty much had enough time to get the dogs in the trunk."

Malibu is one of the most in-demand locations in California for stars seeking privacy and luxury.

Reality TV star Kim Kardashian West, who lives just north of coastal Malibu, revealed she was forced to flee her home.

"I heard the flames have hit our property at our home in Hidden Hills but now are more contained and have stopped at the moment," she said on Twitter. "I just pray the winds are in our favor."

Actor Martin Sheen, briefly reported missing by his actor son Charlie, was also forced to evacuate.

"We're fine, we're at Zuma Beach and we're probably going to sleep in the car tonight," Martin Sheen told Fox News 11, adding that it was the worst fire he had seen in 48 years of living in Malibu.

The wildfire reached Paramount Ranch, destroying the Western Town sets used for hundreds of productions including HBO'S sci-fi western "Westworld," officials and the network said.

Director Guillermo del Toro tweeted that Bleak House, his museum of horror movie memorabilia, was also in the path of the flames.

- Utter devastation -

In Paradise, the flames destroyed hundreds of homes, a hospital, a gas station, several restaurants and numerous vehicles, officials said.

Mandatory evacuation orders were issued for more than 52,000 people in the scenic area in the foothills of the Sierra Nevada mountains.

"The whole lower side of Paradise is totally engulfed in flames right now," Kevin Winstead, a resident of nearby Magalia, told KIEM TV.

"Not one home will be left standing," he said. "I'm devastated."

The National Weather Service said Saturday strong winds and dry conditions were to continue through the weekend. (AFP)