The Pacific Palisades fire between Santa Monica and Malibu led the Los Angeles Fire Department to issue a mandatory evacuation order for a large area from the hills of Topanga Canyon down to the coastline.

Huge billows of smoke could be seen blowing from the hills from miles away as flames encroached on nearby homes. The fire was fuelled by Santa Ana winds that blow warm and dry winds from the inland deserts toward the coast.

“Immediate threat to life. This is a lawful order to LEAVE NOW,” read one notice posted by the California Department of Forestry and Fire Protection (Cal Fire).

Some evacuees walked away from the fire, while others got stuck in traffic in their cars.

Before the fire started, the National Weather Service had issued its highest alert for extreme fire conditions for much of Los Angeles County from Tuesday through Thursday, predicting wind gusts of 80-130km/h with isolated winds of 130-160km/h in the mountains and foothills.

That combined with low humidity and dry vegetation due to a lack of rain.

“In other words, this is about as bad as it gets in terms of fire weather,” the Los Angeles office of the National Weather Service said on X.

Los Angeles mayor Karen Bass ordered emergency measures that mobilised city departments to prepare for downed power lines and trees likely to cause power outages.

Los Angeles fire department captain Erik Scott urged against complacency because of cool winter weather, warning of “explosive wildfire behaviour” in a public service message.