A statue stands in front of a home destroyed at the Oakridge Mobile Home Park in the northern San Fernando Valley area of Los Angeles. (Reed Saxon/Associated Press)Major brushfires were burning in four Southern California counties Sunday, in one of the state's worst ever fire emergencies.

More than 800 homes and apartments have been destroyed in all by the Santa Ana wind-fed fires that have burned close to 88 square kilometres of land since they began Thursday.

In the past four days, 50,000 people have fled their homes, the most recent evacuees coming from San Bernardino County, southeast of Los Angeles.

In Orange County, one fire was burning dangerously close to a mobile home park in the Olinda Village area north of Yorba Linda.

People living in the Chino Hills east of Los Angeles remained on guard through the night and into early Sunday as flames destroyed 168 homes in the area.

Grant McComb talks to a friend on the phone as he keeps an eye on the burning house next door in Yorba Linda on Saturday. (Mark Avery/Associated Press)

The most devastating fire in Los Angeles County in nearly 50 years tore through an upscale mobile home park in Sylmar and reduced 500 trailers to ash on Saturday.

"I spent almost $45,000 in remodel jobs, complete new kitchen, complete new bathroom, complete new roof. Did a lotta good, huh?" said one woman at the Oakridge Mobile Home Park.

Governor Arnold Schwarzenegger declared a state of emergency for Los Angeles, Orange and Santa Barbara counties, but forecasters expected the winds to die down Sunday.

No deaths were reported, but police dogs were searching the rubble of the park, focusing on mobile homes where cars were still parked in front.

Fire officials estimated that at the peak of the Sylmar fire, 10,000 people were ordered to leave. Many returned home later in the day after many of the evacuation orders were lifted.

In Santa Barbara County, 200 homes have been destroyed there since Thursday. However, firefighters say the winds changed direction on Saturday and the fire began moving away from residential areas.

A firefighter is seen on Saturday dragging a hose uphill in Yorba Linda. (Mark Avery/Associated Press)

Firefighters have had to battle record high temperatures, and on Saturday, Santa Ana winds with near-hurricane strength were reported. However, calmer winds on Sunday helped in firefighting efforts.

Smoke hung over the city of Los Angeles from fires to the north and to the south. Parts of the city were briefly without power Saturday as the flames shut down power lines.

"It's an interesting chess game right now," said Capt. Guy Melker of the Los Angeles County Fire Department, as he stood on a balcony of a multimillion-dollar home in Diamond Bar neighbourhood. "Sometimes, Mother Nature puts us in check, and our job is to put her in checkmate."

To the south in Orange County, the winds played hopscotch with fire embers, bypassing some homes and ruining others.

"It was already on this ridge when we got here," said fire captain Greg Lewis. "So we just go from house to house and do what we can. And you can see it's every third house, every fifth house, every sixth house. That type of thing."

With files from the Associated Press