The authorities have reported six more fatalities from a blaze in Northern California, bringing the total number of fatalities so far to 48 in the deadliest wildfire in state history.

The announcement came Tuesday after authorities ramped up the search for more victims buried in rubble left by the blaze that incinerated the town of Paradise.

Many friends and relatives of those living in the fire zone say they haven't heard from loved ones. Some went to shelters looking for them.

More than 5,000 firefighters are still battling the blaze that charred 195 square miles (505 square kilometres) since it started Thursday.

The fire has destroyed about 7,700 homes and displaced 52,000 people.

The statewide death toll from wildfires over the past week in California has reached 50.

The president of a utility accused by some residents of starting a deadly wildfire in Northern California says there was a power outage about 15 minutes before the flames were reported.

Landowner Betsy Ann Cowley says Pacific Gas & Electric notified her the day before the blaze that crews needed to come onto her property because the utility's wires were sparking.

Asked if sparks from a transmission line ignited the fire, PG&E President Geisha Williams told the Chico Enterprise-Record on Tuesday that "it's too soon to tell."

Williams says the outage was at 6:15 a.m. Thursday and later an aerial patrol spotted damage around the transmission lines. She says the company sent a report to state agencies.

She says the sparks are one of several "options" investigators are reviewing.

Some victims sued PG&E on Tuesday, alleging it failed to maintain its infrastructure.

Victims of California's most destructive wildfire have filed a lawsuit accusing Pacific Gas & Electric Co. of causing the massive blaze.

The suit filed Tuesday in state court in California accuses the utility of failing to maintain its infrastructure and properly inspect and manage its power transmission lines.

The utility's president said earlier the company doesn't know what caused the fire, but is cooperating with the investigation by state agencies.

An email to PG&E about the lawsuit was not immediately returned.

PG&E told state regulators last week that it experienced a problem with a transmission line in the area of the fire just before the blaze erupted.

A landowner near where the blaze began said PG&E notified her the day before the wildfire that crews needed to come onto her property because some wires were sparking.

Authorities doing the somber work of identifying the victims of California's deadliest wildfire are drawing on leading-edge DNA technology. But experts say older scientific techniques and deduction could also come into play.

With the death toll from the Northern California blaze topping 40 and expected to rise, officials said they were setting up a rapid DNA-analysis system, among other steps.

Rapid DNA is a term for portable devices that can identify someone's genetic material in a couple of hours, rather than days or weeks.

But more traditional methods, such as examining dental records, are often a first step. Partially, that's because victims might have had dental X-rays but not personal DNA profiles. Other medical records — of bone fractures, prosthetics or implants, for instance — also can be helpful.

As a huge wildfire burns in Southern California, residents who stayed behind in coastal communities cut off by road closures are getting supplies by boat.

Gas, food, baby wipes and horse pellets are among the items brought ashore Tuesday in the Paradise Cove area of Malibu.

Large boats arrived from Redondo Beach, about 25 miles (40 kilometres) to the south. Supplies were unloaded onto smaller boats and even surf boards. Some residents donned wet suits and swam ashore with cases of water and beer.

The fire northwest of Los Angeles has charred 150 square miles (388 square kilometers) of brush and timber, but containment has increased to 35 percent. More than 400 structures have been destroyed.

Some Malibu residents are being allowed to return Wednesday afternoon, but tens of thousands of people remain under evacuation orders.

People are coming to shelters in Northern California in search of loved ones and neighbors who are missing after a deadly fire tore through the town of Paradise.

Greg Gibson searched a shelter in Chico on Tuesday for information about his missing neighbors. He doesn't know if they tried to leave or not but says the fire exploded so quickly that if they hesitated, they would have had trouble.

It's not clear how many people are unaccounted for in the fire that ignited last week. At least 42 people are dead.

Harold Taylor says he barely made it out of his house alive Thursday morning. The 72-year-old Vietnam veteran who walks with a cane says he tried to convince his neighbor to get in his car with him, but the neighbor declined. He doesn't know what happened to his friend.

A fire official says crews have made "a lot of progress" in preventing a deadly Northern California from reaching Oroville, a town of 19,000 people.

California forestry and fire protection operations department chief Josh Bischof said Tuesday that firefighters on foot and in bulldozers are working south of the town of Paradise. It was levelled by the blaze that started last Thursday.

Officials had worried strong winds could spread the wildfire toward Oroville and the Oroville Dam, the nation's tallest. Firefighters on Monday cleared brush and sprayed water on vegetation near the dam.

Bischof says "we're feeling a lot better about this area."

More than 5,000 firefighters are battling the fire that killed at least 42 people in Paradise and nearby communities.

The daughter of one of three named victims from the Northern California wildfire says that Ernie Foss Jr. was a musician and former San Francisco resident who shared his love of music with others.

Angela Loo told KTVU-TV on Sunday that the family is devastated by the death of her father, one of at least 42 people killed by the fire.

She says Foss moved to the town of Paradise eight years ago because of the San Francisco Bay Area's high cost of living.

Loo says he taught music from their home near the city's famous Haight Street and turned their living room into a studio.

KTVU reports Foss and his dog, Bernice, were found outside their home on a street where several other victims were also found.

Foss had advanced lymphedema and could not walk.

The Butte County sheriff's office listed his age as 65, but records show he was 63.

The son of a man who died in the Northern California wildfire says his father will be buried next to his wife in a cemetery in the small town where he died.

The Butte County sheriff's office identified 77-year-old Carl Wiley of Magalia as one of at least 42 who died in the fire.

Magalia and the neighbouring town of Paradise were devastated by the fire.

James Wiley says his father was a tire recapper for Michelin and described him as a stoic figure.

The elder Wiley will share a headstone with his wife, Mary Lee. She died of cancer nearly three decades ago.

Authorities say destruction from Southern California's huge wildfire will be significantly higher than the 435 structures already counted as destroyed.

Los Angeles county fire chief Daryl Osby said at a press conference Tuesday that authorities are assessing damage from the 150-square-mile (388-square-kilometer) Woolsey Fire. Personnel are checking many canyon areas by foot, which will take several days.

Authorities say risk from the fire has dropped significantly, with people going home to many areas that were evacuated when the blaze broke out last Thursday.

Planes and helicopters are attacking a huge flare-up in a mountain wilderness area on the Ventura County side of the fire.

Ventura county fire chief Mark Lorenzen says winds are pushing those flames away from nearby communities and he's confident they're safe.

Forecasters say rain could fall next week, raising concerns about mudflows.

Authorities have identified only a fraction of the dozens of victims of a wildfire that has decimated a Northern California town.

Jesus Fernandez, a 48-year-old Concow resident nicknamed "Zeus," and his beloved dog "King" had been missing since the fire broke out Thursday.

Family friend Myrna Pascua told The Sacramento Bee that Fernandez's son was informed Monday that his father was found pinned between two cars.

The wildfire that largely wiped out the town of Paradise has left at least 42 dead and destroyed thousands of homes and other buildings.

President Donald Trump says there are more victims of the California wildfires "than anybody would ever even think possible."

Trump thanked firefighters, first responders and the Federal Emergency Management Agency for doing their jobs with "courage in the face of very grave dangers."

Dozens of people have died, thousands of homes have been destroyed and thousands of people have been evacuated and in the wildfires scorching both ends of the state.

Trump spoke about the fires Tuesday at the beginning of a White House ceremony about the Hindu festival of lights.

US interior secretary Ryan Zinke says he's cancelled a planned trip to Asia at the direction of the White House and will instead travel to California to support efforts to contain the deadly wildfires scorching large areas of the state.

Zinke said Tuesday he will visit the Northern California fire that wiped out the town of Paradise and killed 42 people. He will travel later to Southern California, where another fire is burning that has killed two people.

Zinke says he plans to meet with California Gov Jerry Brown to offer the administration's support.

The move comes after president Donald Trump — Zinke's boss — on Saturday blamed poor "forest management" for making California's fires so big, deadly and costly.

About 200 people who fled their homes following the most destructive wildfire in California history have packed into a Northern California church where counsellors, chaplains and nursing students from Chico State University were available to help.

The Neighbourhood Church in Chico was one of more than a half-dozen facilities helping house people displaced by the blaze, which has killed at least 42 people.

James Woods is a director at the church and said Tuesday it will stay open "as long as it's needed."

Volunteers are cooking three meals a day, and there is a large bulletin board with information about missing people.

Miley Cyrus and Liam Hemsworth lost their home in the deadly wildfire blazing California but are donating $500,000 to The Malibu Foundation through Cyrus' charity, The Happy Hippie Foundation.

A representative for Cyrus says Tuesday in statement to The Associated Press that the couple's "community and state are very special to them and they want to give back to the place that has created so many beautiful memories for themselves and others."

Cyrus and Hemsworth's home was in Malibu and burned by the big Southern California wildfire that killed two people.

The statement says they "are very grateful to be safe along with their animals."

The statement says the donation "will be used for those in financial need, emergency relief assistance, community rebuilding, wildfire prevention and climate change resilience."

California regulators say initial testing has found no elevated levels of radiation or hazardous compounds after Southern California's huge wildfire burned near a former nuclear test site in hills to the northwest of Los Angeles.

The state’s toxic substance control department says its staff went to the site known as the Santa Susana Field Laboratory on Saturday and found that facilities that previously handled radioactive and hazardous materials were not affected by the fire.

The organization Physicians for Social Responsibility said in statement Monday that it was likely that smoke and ash from the fire spread radiological and chemical contamination that was in soil and vegetation.

But the state agency says its measurements on the site and in the surrounding community found no radiation levels above background levels and no elevated levels of hazardous compounds other than those normally present after a wildfire.

The site was used for decades for testing rocket engines and nuclear energy research. One of its nuclear reactors had a partial meltdown in 1959. Battles over decontamination efforts have gone on for years, with neighbours blaming illnesses on the site.

Fire crews battling a Northern California blaze that levelled a town and killed at least 42 people made gains overnight and prevented the blaze from advancing toward a town of 19,000 people.

California’s forestry and fire protection department said Tuesday that firefighters held containment lines to slow the wildfire's advance toward Oroville.

Officials say more than 5,000 firefighters are battling the blaze that destroyed the town of Paradise and has charred 195 square miles (505 square kilometres) since it started Thursday. The blaze is 30 per cent contained.

Milder winds of up to 25 mph (40 kph) are expected in the area Tuesday. But fire behaviour specialist at Cal Fire Jonathan Pangburn says the there's plenty of bone dry vegetation ready to burn "really fast and hot."

The wildfire has destroyed more than 6,400 homes and displaced 52,000 people.

Firefighters are working to extend containment lines around the vast area burned by a Southern California wildfire.

The work to eliminate the threat from the so-called Woolsey Fire on Tuesday was happening as winds continue to cause high fire threats from metropolitan Los Angeles to San Diego County.

Authorities have allowed more people to return home but several entire communities, including Malibu, remain under mandatory evacuation orders.

The latest estimates show the fire spread over more than 146 square miles (378 square kilometres). The fire area is expected to be fully contained by Thursday.

Authorities have said two people were killed in the fire and at least 435 buildings were destroyed.

More than a dozen coroner search and recovery teams looked for human remains from a Northern California wildfire that killed at least 42 people, making it the deadliest in state history. Anxious relatives are visiting shelters and calling police hoping to find loved ones alive.

Lisa Jordan drove 600 miles (1,000 kilometres) from Yakima, Washington, to search for her uncle, Nick Clark, and his wife, Anne Clark, of Paradise, California. Anne Clark suffers from multiple sclerosis and is unable to walk. No one knows if they were able to evacuate, or even if their house still exists, she said.

Lisa Jordan says she's staying hopeful and adds: "Until the final word comes, you keep fighting against it."

Butte county Sheriff Kory Honea updated the confirmed fatality number Monday night.

The figure that is almost certain to spike following the blaze that last week destroyed Paradise, a town of 27,000 about 180 miles (290 kilometres) northeast of San Francisco.

Authorities were bringing in two mobile morgue units and requesting 150 search and rescue personnel. Officials were unsure of the exact number of missing.