A total of 44 people have been killed in California's devastating wildfire as authorities continue to find bodies in burnt-out cars and homes.

Some remains were found next to cars, with authorities guessing the victims had been overcome by smoke and flames before they could get in their vehicles and drive to safety.

Coroners found charred bone fragments so small that they had to be sifted through a sieve-like wire basket.

Hundreds of people are still unaccounted for, four days after the fire began.

:: Eyewitness - Paradise destruction as complete as Mosul or Raqqa


Image: A pair embrace while looking over the remains of their burned house in Paradise

Helicopter dumps water as fire lashes freeway

The blaze was part of an outbreak of wildfires on both ends of California state.

Together, they were blamed for 44 deaths, including two in celebrity-studded Malibu in Southern California, where firefighters appeared to be gaining ground against a roughly 143-square-mile blaze that destroyed at least 370 structures.

In Northern California, fire crews still fighting the blaze that obliterated Paradise worked against 40mph wind gusts overnight and 300ft flames.

Image: Many people are still unaccounted for

Gerard Butler and the remains of his home

The fire had grown to 177 square miles and was 25% contained, authorities said.

There are more than 8,000 firefighters tackling the blaze in the state.

The popular retirement community of Paradise had a large population of over-65s.

People are desperately trying to get in touch with loved ones to find out if they managed to escape.

Driving through the inferno

The Paradise wildfire from the air

Tad Teays was waiting to find out information on his 90-year-old mother who has dementia, while Darlina Duarte was desperate for information about her half-brother, a diabetic who was largely housebound because he had lost his legs.

And Barbara Hall tried in vain to find out whether her aunt and aunt's husband, who are in their 80s and 90s, made it out alive from their retirement community.

Image: Cars and homes have been reduced to ash

Terrified residents flee for their lives

"Did they make it in their car? Did they get away? Did their car go over the edge of a mountain somewhere? I just don't know," she said, adding that the couple had only a landline and calls were not going through to it.

Megan James, of Newfoundland, Canada, searched via Twitter from the other side of the continent for information about her aunt and uncle, whose house in Paradise burned down and whose vehicles were still there.

On Monday, she asked on Twitter for someone to take over the posts, saying she is "so emotionally and mentally exhausted."

"I need to sleep and cry," Ms James added. "Just PRAY. Please."

Greg Woodcox, who led a caravan of vehicles that was overcome by flames, said he heard screams and watched a friend die as the heat blew out the vehicle's windows.

Image: Authorities have been searching for human remains

Helicopter shows scale of California wildfire

Mr Woodcox told the San Francisco Chronicle he was in a Jeep ahead of the other vehicles and ran when the flames overtook them.

He followed a fox down a steep embankment and survived by submerging himself in a stream for nearly an hour.