Dozens of drivers in California have been forced to abandon their cars as a raging wildfire blows across Interstate 15 (I-15).

The fast-moving blaze began north of State Route 138 in the Baldy Mesa area on July 17, forcing both lanes of the I-15 – the main road between Southern California and Las Vegas – to shut down.

The fire, in the Cajon pass, left at least 20 vehicles on the I-15 in flames. It broke out at the start of the weekend during peak travel time.

There have been no confirmed reports of injuries.

Footage from news helicopters shows dramatic pictures of people walking away from the flames, covering their faces and trying not to breathe in the noxious smoke and fumes.

Several lanes of the road were closed, causing traffic to back up for miles.

Dozens of vehicles have been abandoned – and some are completely engulfed in flames.

Firefighters asked evacuating motorists to leave their keys in the cars – in the hope that they could clear the cars once the fire is under control.

Aircraft are dropping flame retardant chemicals on the fire.

The I-15 is the main road linking Los Angeles and Nevada, and is particularly busy at the weekends as southern Californians head to Las Vegas.

Wildfires are common in California, but have been exacerbated by the four-year drought gripping the state.