A new wildfire erupted north of Los Angeles on Wednesday, quickly growing in size and prompting thousands of evacuation orders in a region already reeling from the aftermath of large blazes.

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

The fire was being fueled by strong, dry Santa Ana winds, pushing a dense cloud of smoke and embers ahead of the flames.

Evacuations were ordered for 19,000 people around the lake, located about 35 miles (56 kilometers) north of Los Angeles, near 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 struck as the greater Los Angeles area was still recovering from two massive fires that killed more than two dozen people and destroyed thousands of structures.

Robert Jensen, from the Los Angeles County Sheriff's Department, urged everyone in the affected area of the new blaze — dubbed the Hughes Fire — 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 through neighborhoods, urging people to evacuate.

The Lake Castaic area is home to four county jails, housing 4,700 people, the American Civil Liberties Union said.

"We have long opposed the expansion of the jail system, especially in dangerous fire zones, and we are gravely concerned for the safety of people incarcerated in those jails," said Melissa Camacho, senior staff attorney with the ACLU SoCal. "We urge our county supervisors to direct the LA Sheriff's Department to immediately organize the transportation needed to evacuate the jails without delay."

The California Highway Patrol said the fire was impacting traffic on the I-5, a major artery that runs the length of the U.S. West Coast.

Helicopters and planes were on the scene, dropping water and retardant on the blaze. That fleet included two Super Scoopers, large amphibious planes capable of carrying hundreds of gallons (liters) of water.

Crews from the Los Angeles County Fire Department and Angeles National Forest were also fighting the fire from the ground.

It was unclear what sparked the fire, but it occurred during red flag fire conditions — when meteorologists warn that strong winds and low humidity create favorable conditions for rapid fire spread.

Smoke was visible southwest of the fire as far as Thousand Oaks and west toward Ventura on the Pacific Coast.