A fast-moving bush fire in the foothills of Southern California, north of Los Angeles, USA, on Friday overran a packed freeway in a mountain pass, destroying four structures in the process.

The fire torched several cars and trucks as drivers scrambled to safety.

The wildfire, which broke out in the drought-parched foothills of San Bernardino County, had grown from 500 acres (200 hectares) to 3,500 acres (1,416 hectares) in a matter of hours, according to the U.S. Forest Service.

The blaze ripped down a portion of the Interstate 15 freeway that links Southern California and Las Vegas, torching 20 vehicles as drivers abandoned their cars and scrambled to safety.

•Photo shows scene of the incident.