0341 GMT July 21, 2018
The Ventura County Fire Department said more than 27,000 people had been told to evacuate as the fast-moving fire in the coastal county north of Los Angeles grew to 45,000 acres (18,200 hectares). More than 150 homes and businesses had already been destroyed, AFP reported.
California Governor Jerry Brown declared a state of emergency over the area, announcing: "This fire is very dangerous and spreading rapidly.
"It's critical residents stay ready and evacuate immediately if told to do so."
The northern part of Los Angeles county was engulfed in thick smoke, leaving the air almost unbreathable as ash fell on the streets. Mayor Eric Garcetti warned residents to remain vigilant for fresh outbreaks.
"This is an extreme weather event and these winds can spread embers far and/or kick small new fires up quickly. We expect five days of this," he tweeted.
A Red Cross evacuation center which had hosted 600 people Monday night was expecting that number to rise to around a thousand by Tuesday, spokesman Fred Mariscal said.
Lexus Deloni, a 20-year-old caregiver who had brought her two young girls, aged one and two, said she had only 45 minutes to evacuate after returning home from a 12-hour shift in the city of Ojai, an hour-and-a-half drive from LA.
"I'm making sure they are eating, drinking, having fun, playing with them," she said, as a man dressed as Santa Claus arrived, much to the delight of the youngsters.
Prospects for containment depended on improving weather conditions.
Strong seasonal gusts known as the Santa Ana winds had registered speeds of up to 55 miles per hour (80 kilometers per hour), the National Weather Service said, predicting they could hit upwards of 80 miles per hour.
Authorities said more than 1,000 firefighters were currently fighting the "Thomas Fire" -- a blaze captured in apocalyptic images with flames sometimes taking on the appearance of a volcanic eruption.
"Fixed wing aircraft and helicopters are expected to attack the fire at daybreak," the Ventura County website said.
Two other large blazes broke out Tuesday -- the Creek Fire, which has so far swallowed 11,000 acres (around 4,500 hectares) and the more contained Rye fire, spread over 1,000 acres.