LOS ANGELES (AFP) - Crews in southern California battled a brushfire on Saturday that at one point spilled onto a busy highway and triggered scenes of panic among terrified motorists.

The flames burned through several dozen cars and trucks that were abandoned by their fleeing owners on the busy I-15 highway leading from Los Angeles to Las Vegas.

An approaching storm could bring rain to douse the flames but also winds that could fan them.

At one point, the entire multi-lane freeway was closed down Friday afternoon, but it had reopened by dawn Saturday.

Nearly 800 firefighters continued to fight the blaze as of mid-afternoon.

The weather was also a factor.

The California Department of Forestry and Fire Protection, or Cal Fire, said the potential thunderstorms could stir up unpredictable winds and "cause erratic fire behaviour."

Moderate rain is possible and southerly winds could push the fire northward toward the threatened homes and other structures, Cal Fire said.

The fire burned or destroyed 44 vehicles and at least four homes, the Los Angeles Times reported.

Local media reported dramatic accounts of people getting out of their cars with fire burning high on both sides of the highway and not knowing which way to run for safety.

TV footage showed flames chewing through cars, an 18-wheel truck and even a boat, and billowing thick black smoke.

Driver Armando Aguilar told KTLA television he had stopped on the highway because of the fire and everything seemed OK until the flames shot up.

"I told my kids, 'get your stuff.' We got our stuff. We started walking up the hill" beside the highway leading up and away from it, Aguilar said.

"I was telling people 'you'd better come out.' All of a sudden, it just came on us," he said of the fire.

He looked sweaty and tired, wearing a sleeveless T-shirt.

Wildfires are a fact of life in southern California, but have been exacerbated by tinder dry conditions as the western US state is gripped by a fourth year of record drought.

THREATENING HUNDREDS OF HOUSES

The I-15 is the main freeway between Los Angeles and Las Vegas in neighbouring Nevada, and is extremely busy on weekends as Angelenos head to and from the gambling and party haven.

The fire was threatening more than 700 houses and other structures in an area of San Bernardino County known as Baldy Mesa.

So far, the blaze has charred 1,400ha of land.

There were no reports of injuries or casualties.

Overnight, because of a separate fire in Angeles National Forest, crews evacuated hundreds of people from campsites, including children.

The LA County Sheriff's Department said 130 children with special needs had been evacuated from the Lion's Camp mountain and that officials planned to return to escort another 170.

It said earlier that some 300 campers were loaded on to buses and removed from a mountain.

The San Bernardino County Fire Department also said on Twitter that 90 girl scouts were evacuated from a nearby campground.