San Francisco Frontiers - New explosive wildfire erupts near Los Angeles

Ferocious flames were devouring hillsides near Castaic Lake, spreading rapidly to cover 5,000 acres (2,000 hectares) in just over two hours.

The fire was being fanned by strong, dry Santa Ana winds that were racing through the area, pushing a vast pall of smoke and embers ahead of the flames.

Evacuations were ordered for 19,000 people all around the lake, which sits around 35 miles north of Los Angeles, and close to the city of Santa Clarita.

"I'm just praying that our house doesn't burn down," one man told broadcaster KTLA as he packed his car.

The fire came with the greater Los Angeles area still suffering after two enormous fires that killed more than two dozen people and destroyed thousands of structures.

Robert Jensen from Los Angeles County Sheriff's Department urged everyone in the impacted area of the new blaze to leave immediately.

"We've seen the devastation caused by people failing to follow those orders in the Palisades and Eaton fires," he said.

"I don't want to see that here in our community as well. If you've been issued an evacuation order, please get out."

Television footage showed police driving around the neighborhood urging people to get out.

Helicopters and planes were on the scene dropping water and retardant on the blaze, footage showed.

That fleet included two Super Scoopers, enormous amphibious planes that can carry hundreds of gallons (liters) of water.

Crews from Los Angeles County Fire Department and Angeles National Forest were also attacking the blaze from the ground.

It was not immediately clear what sparked the fire, but it occurred during red flag fire conditions -- when meteorologists say strong winds and low humidity create conditions ripe for rapid fire spread.

Y.Gomez--SFF