Butte County Sheriff Kory Honea said on Saturday his department has reports of 110 people still missing in the third-deadliest in California history.

Honea says he's hopeful that more of those missing people will be found. The department initially had more than 500 calls about citizens who were unable to reach loved ones.

But he says they've been able to help locate many.

Next he says sheriff's officials will be cross-checking their list with official shelters to search for the remaining missing.

Honea said that a total of 23 people had died in the fire near the town of Paradise, about 290km northeast of San Francisco.

Residents who stayed behind to try to save their property or who managed to get back to their neighbourhoods in Paradise found cars incinerated and homes reduced to rubble.

People surveyed the damage and struggled to cope with what they had lost. Entire neighbourhoods were levelled and the business district was destroyed by a blaze that threatened to explode again with the same fury that largely incinerated the foothill town.

The flames razed more than 6700 buildings, almost all of them homes, making it California's most destructive wildfire since record-keeping began.

Sheriff's deputies recovered human remains from at least five homes as they went house-to-house in Paradise looking for the missing.

Meanwhile two more people were killed in the south, near Malibu. The Woolsey fire, about 800km to the south, was five per cent contained on Saturday night.

More firefighters headed to the Paradise area on Saturday, with wind gusts of up to 80km/h expected, raising the risk of conditions similar to those when the fire started on Thursday.

The blaze grew to 400sq/km but crews made gains and it was partially contained, officials said.

People sidestepped metal that melted off cars and jet-skis and donned masks as they surveyed ravaged neighbourhoods despite an evacuation order for all of Paradise, a town of 27,000 founded in the 1800s.

Abandoned, charred vehicles cluttered the main thoroughfare, evidence of the panicked evacuation as the wildfire tore through on Thursday. The dead were found mostly inside their cars or and outside vehicles and homes.

State officials put the total number of people forced from their homes by California's fires at more than 200,000. Evacuation orders included the entire city of Malibu that is home to some of Hollywood's biggest stars .

President Donald Trump issued an emergency declaration providing federal funding for fires on both ends of the state. He later threatened to withhold payments to California, claiming its forest management is "so poor."

Trump tweeted on Saturday that "there is no reason for these massive, deadly and costly fires in California".

Trump said "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!"

California Governor-elect Gavin Newsom responded on Twitter that this was "not a time for partisanship."

"This is a time for co-ordinating relief and response and lifting those in need up," he said.

Trump took a more empathetic tone later in the day, tweeting sympathies for firefighters, people who have fled their homes and the families of those killed by the flames.

Australian Associated Press