A fast-moving brush fire in the Southern California foothills overran a packed freeway in a mountain pass on Friday, destroying four structures and torching 20 vehicles as drivers abandoned their cars and scrambled to safety.

The wildfire, which broke out Friday afternoon 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, forcing about 60 drivers to flee their cars on Cajon Pass.

There have been no injuries, the U.S. Forest Service said.

Television images showed fire-fighting aircraft dropping water onto burning vehicles. Several cars and two tractor-trailer rigs, one carrying new vehicles, were in flames.

Twenty vehicles were destroyed and 10 were damaged, the Forest Service said.

Four structures have been gutted by flames and several mountain communities were facing possible evacuations as crews battle to contain the blaze, it said.