About 1,500 people have fled and three are injured as a wildfire in the southern California mountains quickly spreads.

The California wildfire that claimed the lives of two firefighters, ravaged more than 250 square miles and destroyed more than 60 homes was started deliberately, the US Forest service said today.

Calmer winds helped crews fighting a massive wildfire today that killed four firefighters and critically injured a fifth, while investigators searched for the arsonist who set the blaze roaring through the canyons of Southern California.

FIRE crews yesterday struggled to protect homes from a wind-whipped wildfire that trapped and killed four firefighters in a wall of flames as it raced across almost 38 square miles in southern California.