MALIBU, Calif. (AP) — Firefighters battled a brushfire early Tuesday in Malibu, near Pepperdine University, prompting evacuations amid dangerous fire conditions because of Southern California’s notorious Santa Ana winds.

It was not immediately known how the blaze, named the Franklin Fire, started but Los Angeles County Fire Department officials estimated that at least 1.3 square miles (3.4 square kilometers) had burned and structures were threatened, according to KTLA-TV.

Pepperdine canceled classes and finals for the day and there was a shelter-in-place order. Flames could be seen from the campus, according to a university statement. Fire engines were on campus and helicopters were dropping water collected from lakes in the school's Alumni Park onto the fire.

North to northeast winds were forecast to increase to 30 to 40 miles per hour (48 to 64 kph) with gusts up to 65 mph (105 kph) expected, The National Weather Service Los Angeles office posted on X.

Power to tens of thousands of people had been shut off by Monday night as utilities worked to mitigate the impacts of Santa Ana winds, whose strong gusts can damage electrical equipment and spark wildfires.

The Weather Service issued a red flag warning for high fire risk with a rare “particularly dangerous situation,” or PDS, designation starting at 8 p.m. Monday into Tuesday for Los Angeles and Ventura counties.

The L.A. County Fire Department issued a mandatory evacuation order for residents living east of Malibu Canyon Road and South of Piuma Road. University officials said they were monitoring the situation.

Malibu has about 10,000 residents, but the number of those affected by the evacuation order wasn't immediately known.