Thousands of people are under evacuation orders in southern California as a fast-moving wildfire destroys their homes, according to authorities, with the National Weather Service issuing a red alert that described the situation as "particularly dangerous".
Fierce seasonal winds were casting embers up to five kilometers from the seat of the fire around Camarillo, with new spots burning on hillsides, farmland and in residential areas.
The Mountain Fire grew rapidly from a standing start early on Wednesday, and by the following day had consumed 20,000 acres 8,100 hectares, with towering flames leaping unpredictably and sending residents fleeing.
Video shot by an eyewitness showed residents scrambling to leave their homes in Camarillo as thick smoke blanketed the sky above. Footage also showed houses and cars engulfed in flames.
The fire department in Ventura County, northwest of Los Angeles has said that it has asked for additional helicopters to assist in its efforts.
At least two people were injured and several structures damaged or destroyed by the fire in Ventura County, the fire department added.
California Governor Gavin Newsom said the Mountain Fire prompted evacuation orders for over 10,000 people and threatened 3,500 structures.
Schools in Ventura County are closed until at least tomorrow, the county's office of education said.
The fire expanded in size yesterday after powerful winds came into contact with very dry air.
Southern California Edison began shutting off power to customers in areas where the company's equipment was considered at high risk of sparking a wildfire, according to the Los Angeles Times.
"It's bad out there, but we're getting them all out," one woman told local broadcaster KTLA as she drove horses out of the area.
"(The fire) was surrounding on both sides ... It's just all over the place. It's not one clear fire line. It's everywhere."
Ventura County Fire Chief Dustin Gardner said: "Every helicopter, every fixed wing aircraft, everything we've been able to get a hold of is here fighting this fire, and it is moving at a dangerous rate.
"Bushes are burning, grass is burning, hedgerows are burning, agricultural fields are burning, and structures are burning.
"This fire is moving dangerously fast."
He said the blaze's erratic behaviour is extreme and urged everyone to follow instructions from law enforcement.
"When you get an evacuation order from the sheriff, leave. Your homes can be replaced. Your lives can't. Leave."
Gail Liacko said she had to flee her home very suddenly on what had appeared to be a "normal morning".
"All of a sudden there was soot on our patio furniture, coming from the front of the house as well as the back, and the smoke was kind of surrounding our street," she said.
She and her husband quickly began to throw things together.
"It was just very surreal. You just don't know what to pack in a moment of absolute panic."
Another blaze has broken out in Malibu, threatening multi-million dollar homes on some of the most desirable coastline in southern California.
The United States is experiencing a strong wildfire year with 8.1 million acres burned to date, compared with an annual, full-year average of around seven million acres over the last decade, according to National Interagency Fire Center data.
California wildfires have this year burned more than three times as much land as last year when the state's fire season was more benign, according to Cal Fire data.
