A rapidly growing wildfire broke out north of Los Angeles, while two major fires burning in the metropolitan area for more than two weeks were getting under control, fire officials said.

Ferocious flames devoured hillsides near Castaic Lake on Wednesday, spreading rapidly to cover more than 9,400 acres (3,800 hectares) in just a few hours.

Evacuations were ordered for 31,000 people around the lake, which sits 56km (35 miles) north of Los Angeles, and close to the city of Santa Clarita.

The United States Forest Service said the entire 700,000-acre (2,800sq-km) park in the San Gabriel Mountains was closed to visitors.

As the new fire raged, the two deadly fires that have ravaged Los Angeles came under greater control, the California Department of Forestry and Fire Protection (Cal Fire) said.

Since the two fires broke out on January 7, they have burned an area nearly the size of Washington, DC, killed 28 people and damaged or destroyed nearly 16,000 structures, Cal Fire said.

Private forecaster AccuWeather projects damage and economic losses at more than $250bn.