THE largest and most destructive of the wildfires ravaging southern California has destroyed more than 430 homes and buildings north-east of Los Angeles.

The wind-whipped blaze has burned nearly 180sq miles of Ventura County, stretching from hilly forests to the Pacific Ocean.

It is only five per cent contained and gusty Santa Ana winds that have driven the fire are expected to continue, threatening thousands of homes. Dozens of trailer homes in a retirement community were destroyed by the fire.

The fire tore through the Rancho Monserate Country Club community in Fallbrook, known for its avocado orchards and ranches, hospitalising at least two people with burns.

As the flames approached the elite San Luis Rey Downs training facility for thoroughbreds, many of its 450 horses were cut loose to prevent them from being trapped in their stalls but some perished.

The fire prompted the closure of state Highway 76 in both directions and evacuations near the Camp Pendleton Marine Corps Base. Evacuation centres were set up in schools and casinos.

Along the coast between Ventura and Santa Barbara, beach communities were under siege as fire raged from steep hillsides across US Highway 101.

Describing her ordeal after evacuating her horses from Ojai, Wendy Frank said: “We drove through a wall of flames.”