Los Angeles - California Governor Arnold Schwarzenegger declared a state of emergency Tuesday as wind-whipped wildfires roared close to Los Angeles killing two people, destroying dozens of structures and forcing thousands to flee.

The Senson and Marek fires burnt some 5,000 hectares in the mountains that ring the San Fernando Valley just north of Los Angeles, sending up huge plumes of thick grey smoke that were visible from the city.

A third fire burnt a further 800 hectares at Camp Pendleton, a massive Marine base near San Diego.

All told, more than 2,000 firefighters were trying to battle the blazes, aided by dozens of water-dropping aircraft, authorities said.

Lighter-than-expected winds helped fire crews limit the damage, with the Marek fire 70 per cent contained by Tuesday noon. Earlier Schwarzenegger had warned that conditions were perfect for it to spread.

"Once again, we are facing the perfect storm of high winds, low humidity and high heat," said Schwarzenegger at the firefighters' command post.

The Marek fire was the first major blaze of the autumn season, which is traditionally the most dangerous wildfire period in the region. Hot Santa Ana winds gust in from the deserts to the east and whip the smallest sparks into uncontrollable infernos.

Last October, fires forced more than 500,000 people to evacuate, damaged or destroyed an estimated 2,000 homes and caused upwards of 2 billion dollars in damage.

The fires had burnt at least 30 homes and dozens of commercial structures Tuesday. One person died when his car smashed into other vehicles forced to stop when the fire shut down a freeway. The second fatality was a transient who was trapped in a makeshift shelter.

Fire officials warned Tuesday that without a let up in the wind, the fire could burn all the way to the Pacific coast some 25 kilometers away.

"The fire wants to make its way to the coast, and we're going to do our level best to stop it," said Los Angeles fire department spokesman Brian Humphrey. "Two-thirds of our department is on the line."

Schwarzenegger warned communities in the path of the fire to be prepared for the worst and to evacuate immediately when asked.

"Winds are causing fire conditions to change by the hour, which is why it is so important that residents in the areas surrounding these wildfires heed warnings from public safety officials to evacuate," he said. (dpa)