A firefighter douses a burning home with water in northern Los Angeles. (AP)

Los Angeles, Nov. 15 (Reuters): A wildfire fanned by hurricane-force winds ripped through the northwestern Los Angeles foothills today, forcing some 10,000 people to flee their homes and threatening the power supply of California’s largest city.

A separate fire burned a second day in the celebrity enclave of Montecito, where 111 homes have been destroyed.

Los Angeles mayor Antonio Villaraigosa said the fire in the foothills near Sylmar had already destroyed dozens of structures — more than any other in the past decade — and that the flames could take down power lines feeding the city. “The fire is threatening the power of the city of Los Angeles,” Villaraigosa told a news conference. “We may have to move to rolling blackouts.”

He urged residents to conserve power to avoid outages and to evacuate if they were in the fire's path. “If you wait until the fire gets there you have waited too long,” Villaraigosa said.

Police closed down Interstate 5, the main freeway linking Los Angeles to the north, and other roads as 600 firefighters mobilised. Transmission lines bringing power follow the I-5 corridor through the mountains north of the city.

Television showed mountains engulfed in flames and billows of smoke as the sun rose today and Los Angeles County Fire Department spokesman Sam Padilla said the fire was spreading. High temperatures have dried out the vegetation, making them especially vulnerable, and when the wind picks up, it can carry the flames swiftly across large swathes, Padilla said.

About 2,600 acres were burned so far and gusts in the area exceed 120kmph. A map of the fire is at http://tinyurl.com/sayrefire.

Firefighters, two of whom have suffered minor injuries, are trying to stop the blaze before it reaches Santa Clarita, a bedroom community about 64km from the centre of Los Angeles.