Firefighters in Southern California are continuing to battle out-of-control wildfires on Monday that killed one person, injured more than a dozen and forced the evacuation of some 265,000 residents.

By evening, more than a dozen fires had spread across more than 800 square kilometers of drought-stricken land.

At least 600 buildings have been destroyed, including 500 homes and 100 commercial properties, while thousands more are threatened. California officials are desperately asking for help from neighbouring states.

California Gov. Arnold Schwarzenegger declared a state of emergency in the seven affected counties on Monday, opening the door for government aid in what some officials have called the worst spate of fires in the state's history.

"Anything the mayor needs, anything San Diego needs, we are there," Schwarzenegger said Monday during a press conference. "The fire is fast moving. Many of the structures have been already destroyed."

In the community of Lake Arrowhead, in the San Bernardino National Forest east of Los Angeles, two separate wildfires engulfed 128 homes.

Schools buses and ambulances were used to evacuate hundreds of patients from a hospital and nursing homes in Poway, San Diego, sheriff's officials said Monday.

In Orange County, heavy smoke has forced officials to evacuate more than a thousand inmates from a jail and bus the prisoners to another facility in Irvine.

San Diego's Qualcomm Stadium, home to the NFL's Chargers, was turned into an evacuation centre, where thousands of people huddled and watched TV reports on the disaster.

Fairgrounds, high schools and senior centres were also used as evacuation centres for the 250,000 people who were told to leave San Diego County.

The flames are being driven by the hot, dry Santa Ana desert winds and were also responsible for the evacuation of tens of thousands of residents and the destruction of 25 homes in Malibu.

Fires merged and new blazes sprouted on Monday adding to the nearly 400,000 acres already devastated by flames. Nearly 100,000 acres have been burned in San Diego alone.

One of the fires, in Orange County, is believed to have been set by arsonists. Other blazes, threatening the homes of celebrity-laden Malibu, are believed to have been caused by power lines.

San Diego Coutry firefighters said fires were spreading so fast that authorities couldn't accurately count the number of houses destroyed.

"It was nuclear winter. It was like Armageddon. It looked like the end of the world,'' Mitch Mendler, a San Diego firefighter, told The Associated Press.

San Diego Mayor Jerry Sanders called on residents to look out for their neighbours, support those who are being evacuated and to "make sure we do this in an orderly and safe way so that we don't lose anybody to some type of injury that was caused by panic."

"Now it's time for San Diegans, no matter where you live in this county, to work together," he said.

Fire officials said crews were unable to fight the fires in some areas because they were busy rescuing residents who refused to leave.

"I urge everyone to follow the directions and evacuation orders issued by emergency personnel," Schwarzenegger said earlier in the day.

Schwarzenegger said emergency crews have contained about 10 per cent of the fires.

Los Angeles County Supervisor Zev Yaroslavsky said the weather conditions have created a "perfect storm."

"The fire department and law enforcement personnel have been stressed almost beyond the point of reason because there are so many fires going, mutual aid has been stretched to its limits," Yaroslavsky said Monday.

He stressed residents must be vigilant with their personal safety and that fires can pop up in any given area.

"The winds are erratic, they are unpredictable and there is no telling where the fires will move and when," Yaroslavsky said.

Celebrity homes threatened

Malibu has many multi-million dollar homes along the Pacific Coast Highway including those owned by David Geffen, Barbra Streisand and Pierce Brosnan.

Celebrities, including James Cameron, Mel Gibson and Olivia Newton John, are among residents being forced to evacuate their homes. Homes belonging to Mark Hamill and David Duchovny are also in danger.

A ranch owned by Sean Penn burned Sunday. The actor's property atop Carbon Canyon also burned in the 2003 Malibu fire.

Fire also destroyed the landmark Castle Kashan, a fortress-like area home in Malibu, as well as the Malibu Presbyterian Church.

"The big problem out here has been the wind," CNN reporter Thelma Gutierrez told CTV Newsnet Monday from Malibu.

"As we were driving in we could actually feel the van shifting from the force of the wind. Also we saw a big plume of black smoke, indicating that several of the areas out here are still burning."

Gutierrez said firefighters are battling the blaze from above using Super Scooper planes that carry 1,600 gallons at a time.

"It can go into the very steep ridges, the canyons, and then drop the water onto the fire," she said.

With files from The Associated Press