At least 1,100 homes and several schools have been evacuated as dry, gusty winds send smoke from a wildfire into a community in the foothills of the San Bernardino Mountains in California, authorities say.
The mandatory evacuations were ordered on Wednesday due to the smoky conditions in parts of Rancho Cucamonga, a city of 165,000 people east of Los Angeles.
The fire has burned at least 80 hectares of brush sapped of moisture by two days of Santa Ana winds, unseasonably high temperatures and low relative humidity.
Gusts of 95kph prevented firefighting helicopters from taking to the air, CalFire spokeswoman Liz Brown said.
"They are not able to get off the ground so we are fighting this with ground resources right now,'' she said.
Classes were cancelled at the local Los Osos High School about an hour after the fire started.
"We're evacuating cause there's high winds and there's a fire right up there," student Shane McHale told KTTV, pointing to the mountains.
Meanwhile in San Diego County, sheriff's officials said a handful of residents evacuated their homes when a fire broke out in a riverbed near a golf course in Santee.
The fire was contained about an hour later, but another flare-up burned palm trees, and high winds kept the area in some danger.
Red flag warnings of high fire danger were posted by the National Weather Service for parts of Southern California until 8pm on Thursday.