California wildfire death toll climbs to 42; several missing

Thousands of firefighters spent the fifth day Monday digging battle lines to contain California's worst ever wildfire as the wind-whipped flames cleaved a merciless path through the state's northern hills, leaving death and devastation in their wake.

A devastating blaze in northern California has become the deadliest wildfire in the history of the state, with 42 people killed, a sheriff said on Monday.

"As of today, an additional 13 human remains have been recovered, which brings the total number to 42," Sheriff Kory Honea told a news conference.

After originally saying it was the deadliest wildland fire in US history, Honea clarified that it was the deadliest ever in California.

As well as the historic loss of life, the blaze is also more destructive than any other on record, having razed 6,500 homes in the town of Paradise, effectively wiping it off the map.

Some 4,500 firefighters from as far as Washington and Texas have been working to halt the advance of the inferno as "mass casualty" search teams backed by anthropologists and a DNA lab pick through the charred ruins to identify remains -- sometimes reduced to no more than shards of bone. 

On the ground, cars caught in the flames have been reduced to scorched metal skeletons, while piles of debris smoulder where houses once stood, an occasional brick wall or chimney remaining.

The Camp Fire has matched the 1933 Griffith Park disaster in Los Angeles -- until now the single deadliest wildfire on record -- according to the California Department of Forestry and Fire Protection (Cal Fire).

Police say 228 people are unaccounted for in the Paradise area, although many may be among the 1,400 in emergency shelters outside of the danger zone. 

The blaze has consumed around 85,500 acres (34,600 hectares), destroyed at least 177 buildings and was only 15 per cent contained, Cal Fire said.

Singer Miley Cyrus's home was one of the buildings destroyed in southern California.

"Completely devestated (sic) by the fires affecting my community. I am one of the lucky ones. My animals and LOVE OF MY LIFE made it out safely & that's all that matters right now," she tweeted.

"My house no longer stands but the memories shared with family & friends stand strong," she said.