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

The wildfire, which broke out on Friday afternoon in the drought-parched foothills of San Bernardino County, had grown from two square-kilometres to more than 14 square-kilometres in a matter of hours, according to the US Forest Service.

The blaze ripped down a portion of the Interstate 15 highway that links Southern California and Las Vegas, forcing about 60 drivers to flee their cars on Cajon Pass.

There have been no injuries, the US Forest Service said.

Journalist Jim Dalrymple tweeted the following footage from the area.

Lance Andrade, a 29-year-old railroad conductor, was stopped in traffic when the fire jumped the highway and panicked people started running towards him. He also ran, but with flames all around, there was nowhere to go.

He, four other men, and two elderly women got inside the back of a semi-truck. One of the women had been separated from her family began crying, and everyone was terrified.

"You could hear the explosions from people's vehicle tyres popping from the heat," Andrade told the AP news agency. "You could hear crackling, smoke was coming in every direction. You could feel the heat. We just waited it out and prayed to God."

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.

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

The interactive map below is updated in real-time. It shows wildfire locations, perimeters and weather conditions.

Source: Al Jazeera and agencies