"So listen carefully and immediately move as soon as they tell you to move."

Firefighters killed

Two firefighters were killed when their vehicle rolled off a mountainside as they battled a blaze in the Angeles National Forest. Four others were injured.

Three civilians suffered burns, including two who tried to ride out the fire by sitting in a hot tub.

The blazes had destroyed an area of 140 square kilometres and at least 18 homes, the US Forest Service said.

The fires are expected to spread amid hot temperatures and low humidity.

More than 6,000 firefighters have been battling the blaze and trying to build more than 160km of fire protection lines.

The west coast state of California is frequently hit by wildfires.

In 2007 it suffered the worst blazes in its history, forcing the evacuation of 640,000 residents and destroying about 2,000 homes.