Officials think the fire was started deliberately

Several thousand people have been evacuated, as the flames move towards built-up areas.

Hundreds of firefighters are trying to contain the blaze in San Bernardino county, about 80 kilometres (50 miles) east of Los Angeles.

Strong winds mean the direction of the fire is hard to predict.

We got out what was important, and what's most important is us Christiane Elin

Some 5,000 hectares have been burnt, as well as homes and vehicles. Officials estimate the damage at $1.7m.

The authorities say they think the fire which broke out on Tuesday was started deliberately.

Winds and dry weather have fanned the thick, black smoke, choking communities and forcing two major freeways to close.

"It looks like night time here," said Kelly Bocanegra, an elementary school teacher.

Sprinklers

San Bernardino County Fire Department spokesman Gil Sanchez said around 2,000 people had been evacuated in the areas of Fontana and Rancho Cucamonga.

He said only 17% of the fire had so far been brought under control.

"We got out what was important, and what's most important is us," said Christiane Elin who was among hundreds of people gathered at a high school serving as an evacuation centre in Rancho Cucamonga.

Local communities are under threat

Police and fire officials drove through neighbourhoods ordering residents to get out and waste no time gathering their belongings.

Some of the evacuees turned on their garden sprinklers in a desperate bid to save their homes, said Reuters news agency.

Interstate 15 - the main road to Las Vegas - and Interstate 210 were shut down in both directions causing traffic chaos.

Firefighters are also tackling blazes in Ventura County and at Camp Pendleton Marine Corps Base, 80km (50 miles) north of San Diego.