Wildfires have roared through canyons, hillsides and residential areas in densely populated Southern California for a fourth day, while gusting winds hampered firefighters' efforts to knock down the flames.
- The four major fires have destroyed hundreds of homes
- There are fears winds of up to 120kph will whip up the fires
- The fires have reached the wealthy enclave of Bel-Air
Some 200,000 people have evacuated ahead of the fires, which have destroyed hundreds of homes and forced hundreds of Los Angeles-area schools to close.
Authorities fear the four major fires — ranging from Los Angeles up the Pacific coast to Santa Barbara County — could be whipped up by the region's notorious westward Santa Ana winds that could reach hurricane strength.
The winds, which blow in hot and dry from the California desert, could reach 120 kilometres per hour and create "extreme fire danger," according to an alert sent by the countywide emergency system in Los Angeles.
The National Weather Service said high winds were expected to continue until Saturday.
The fires, which broke out on Monday and Tuesday, have reached into the wealthy enclave of Bel-Air on Los Angeles' West Side. Some major highways in the densely populated area were intermittently closed.
No civilian casualties or fatalities have been reported but three firefighters were injured, the Los Angeles Fire Department said.
The Los Angeles Unified School District, the country's second largest with more than 640,000 students, said it closed at least 265 of its nearly 1,100 schools.
Dozens of schools also were closed in neighbouring Ventura County, where the largest of the area blazes, the Thomas Fire, has charred more than 38,850 hectares.
Heavy smoke leads to health warnings
The fires created hellish scenes of flaming mountains and walls of smoke as firefighters sprayed water and helicopters dumped loads to contain the flames.
"You don't expect things like this," Jake Sandell, a resident of Santa Paula in Ventura County, said.
"I was expecting this year to see snow on that mountain and now the thing is on fire."
Because of the heavy smoke, the South Coast Air Quality Management District warned residents, especially the elderly, children, pregnant women and people with respiratory diseases, to stay inside.
The Thomas Fire, the largest in the area, continued its westward push on Thursday, forcing a few hundred Santa Barbara County residents to be evacuated and the closing of coastal Highway 101 north of Ventura city.
The fire has destroyed more than 150 homes and threatened thousands more in Ventura.
In the San Fernando Valley north of Los Angeles, the Creek Fire destroyed at least 30 homes, blackened more than 4,800 hectares and forced the evacuation of 2,500 homes and a convalescent centre.
Another blaze, the Rye fire, threatened more than 5,000 homes and structures northwest of Los Angeles.
Blaze threatens affluent Bel-Air neighbourhood
The Skirball fire in Los Angeles has forced hundreds of residents in the wooded hills near the affluent Bel-Air neighbourhood to evacuate and charred more than 192 hectares.
Skirball threatened media magnate Rupert Murdoch's Moraga Estate winery. The property was evacuated, with possible damage to some buildings, Murdoch said in a statement.
Additional evacuations were called for in the Ventura area, where 50,000 people had already fled their homes over the last three days.
About 100 firefighters fended off flames in the seaside enclave of Faria Beach, caught between burning mountains and the Pacific Ocean, northwest of Ventura.
Fires spread down the smoking hills, jumping the heavily used US 101 highway, and headed toward clusters of beach houses. Firefighters lined up along a railroad track, the last barrier from the flames.
The fires are the second outbreak to ravage parts of California this autumn.
The celebrated wine country in the northern part of the state was hit by wind-driven wildfires in October that killed at least 43 people, forced some 10,000 to flee their homes and consumed at least 9,900 hectares north of the San Francisco Bay area.
The California Department of Insurance said the northern California blazes caused insured losses of more than US$9 billion ($12 billion).