Remains have been recovered from at least 42 people killed by a devastating wildfire that largely incinerated the town of Paradise in
northern California, making it the deadliest in US history, the Butte County sheriff said on Monday.

The latest death toll was announced after authorities located the remains of 13 additional victims from the Camp Fire, which also ranks as the most destructive on record in California, having levelled more than 7,100 homes and other buildings since it erupted on Thursday, officials said.

The number of people killed by the fire had stood at 29
earlier in the day.

Meanwhile, experts in identifying human tissue joined California police and firefighters on Monday in sifting through the charred debris of homes destroyed in the fire, searching for remains of 228 missing people.

University anthropologists, trained in spotting bone fragments and other blackened body parts, systematically mined the ash and detritus of buildings wiped out in the wildfire.

For friends and relatives of the unaccounted-for in and around the town of 26,000 residents, the wait has been excruciating, knowing that the remains of some of the dead may never be recovered.

"In some cases, the fire burned so intensely that it burned everything to the ground, and in some cases, it melted the metal," Butte County Sheriff Kory Honea told reporters on Sunday. "In those cases, it is possible the temperatures were high enough to completely consume the body."

The Camp Fire, which has forced 53,000 evacuations, was still only 25 percent contained on Monday, having scorched 113,000 acres and destroyed more than 6,700 structures, the most in California's recorded history, the California Department of Forestry and Fire Protection, known as CalFire, said.

Four forensic anthropologists from Nevada's Clark County coroner's office have been deployed to the Paradise fire, the county said in a statement. Clark County includes Las Vegas, the scene of the nation's largest mass shooting just over a year ago.

Nearly 1,400 survivors were sheltered in official evacuation centres, CalFire spokesperson Erica Bain said, and nearly all of them had communicated with loved ones about their whereabouts.

People still looking for the missing have been directed to call centres for updates.

Teams dressed in white or yellow coveralls picked through the debris by hand or with small garden shovels, hoping to find remains that could be transferred to Butte County facilities to be examined by pathologists.

In addition, the California Department of Justice deployed a mobile unit to help collect DNA from relatives of Camp Fire victims in order to positively identify the dead, the San Francisco Chronicle reported.

Nine law enforcement agencies had 42 people assigned to the search, in addition to 45 anthropologists from several institutions such as nearby California State University Chico and firefighters from 14 CalFire engine companies, said Megan McMann, community relations coordinator for the Butte County Sheriff's Office.

"The area is not safe for dogs at this point, but we are working with CalFire to make the area safe so we can begin introducing cadaver dogs," McMann said.

In the meantime, anthropologists were applying skills also used to recover ancient remains

Eric Bartelink, co-director of Chico university's Human Identification Lab, said his team frequently conducts searches of fire scenes and for buried bodies, but rarely so close to home.

"We have friends and relatives that were affected by the fire," Bartelink told the Mercury News. "We know that there was a massive loss of life with these fires as we're hearing from the Sheriff's Office, and so we're here to help and provide closure for families."

--Reuters