Firemen and the raging inferno in Los Angeles

Firefighters in California struggled to contain a new fast-moving blaze on Wednesday that threatened thousands of homes and the Ronald Reagan Presidential Library.

In much of Los Angeles region, authorities issued a rare “extreme” red flag warnings.

The so-called Easy Fire in the Simi Valley northwest of Los Angeles erupted around 6:00 am, forcing the evacuation of the library and nearby homes as it spread to more than 1,500 acres (526 hectares), officials said.

Fire crews raced to protect the hilltop library surrounded by dense brush, as helicopters and aircraft dropped water and fire retardant on the flames that were fed by powerful wind gusts.

Horses and other animals at area ranches were also being evacuated, with people rushing from outside the region to help.

“The fire outflanked us very rapidly, pushed by those 40 to 50 mile-per-hour winds,” Ventura County Fire Assistant Chief Chad Cook told reporters. “We did experience gusts up to 65 miles an hour this morning, which made long-range spotting very very dangerous and also quickly outpaced the initial attack resources.”

Ventura County Sheriff Bill Ayub said 7,000 homes were under mandatory evacuation orders affecting some 26,000 residents.

Melissa Giller, a spokeswoman for the library, told local radio that the archives and much of the memorabilia from the Reagan administration and from his time as governor of California were safely stored in an underground fireproof vault at the facility.

The flames were closest to a pavilion housing a former Air Force One aircraft. By late afternoon, the fire had spared the building, though authorities warned the situation could quickly change because of the fierce winds that can spread embers for miles.

“It was a crazy morning, it was unexpected,” Duke Blackwood, executive director of the library told AFP. “At this point, most of the fire danger is out but there (are) still a lot of hot spots and smoke.”

Authorities said it was unclear what caused the fire, which started near Easy Street and raced through hillsides toward neighbourhoods.

The fire broke out amid “critical” or “extremely critical” red flags warnings in parts of southern California because of powerful so-called Santa Ana winds, with potential gusts of up to 80 miles per hour (130 kilometers per hour) in mountainous areas.

“We expect the Santa Anas to be howling,” the National Weather Service said, adding that the red flag warnings were in effect through Thursday evening.

Some 18 million Californians live in the areas affected.

Several other brush fires also erupted throughout the day Wednesday in other areas of southern California, stretching resources and creating a traffic nightmare.

Closer to Los Angeles, firefighters were battling the Getty Fire, which began near the famous Getty Center museum on Monday and by Wednesday afternoon had burned 745 acres, with 27 percent containment.

Authorities said they feared the fire, which was caused by a tree branch that fell on power lines, could spread because of the strong winds expected to last through Thursday evening.

Still, evacuation orders were lifted Wednesday afternoon for most people affected by the blaze.

Los Angeles Fire Department spokeswoman Margaret Steward said that in anticipation of the record-strong Santa Ana winds, all staff had been mobilized and additional backup brought in.