A major highway closed by a wildfire was reopened on Saturday but officials warned smoke or firefighting could bring fresh closures and motorists should avoid the immediate area.

Firefighters were still battling the blaze in a desert area east of Los Angeles, according to the Incident Information System website InciWeb, which tracks major wildfires across California.

The fire had broken out in the Cajon Pass on Friday in the early afternoon on a median of Interstate 15, the main artery between Southern California and Las Vegas, and the highway was closed much of Friday.

Motorists are advised to avoid Cajon Pass as traffic may back up if closures occur again, InciWeb said on Saturday.

The fire burned at the edge of Oak Hills, where 1,500 homes were put under a mandatory evacuation order, authorities said.

Hundreds of firefighters had been brought in to try to control the wildfire.

It's basically right to the south of the community right now, threatening homes, San Bernardino National Forest fire information officer Carol Underhill had said on Friday, referring to Oak Hills, a rural enclave of 9,000 people in the foothills north of the pass.

The Incident Information site reported at least one home heavily damaged, two mobile homes lost and two other structures damaged. It said that overnight the fire laid down with low temperatures and light winds.

Two firefighters were injured, Forest Service spokesman Bill Sapp said, one who suffered heat exhaustion and another who was taken to an area hospital by medical helicopter with unknown injuries.

Resources on the fire included 72 fire engines, five bulldozers, five helicopters and 14 air tankers.