Firefighters in southern California have contained two wildfires but scorching temperatures and dry winds are keeping the region on alert for more blazes.
"This is a very difficult firefight. This is an urban wildland firefight, so it is definitely more difficult than you would see in a more rural setting," said Cal Fire captain Mike Mohler.
Southern California including Los Angeles has been bracing for record temperatures over 100 degrees Fahrenheit (38 degrees Celsius) this week, with authorities opening cooling centers for those otherwise unable to escape the heat.
California and other western US states are routinely hit with wildfires during the summer and fall, but blazes have occurred earlier in the year in recent times.
Los Angeles County firefighters battle a fire at an apartment building under construction next to the Harbor CA-110 Freeway in Los Angeles. (Photo: AP)
The fire charred brush along the nearby Interstate 5 freeway which runs up and down the West Coast, at one point forcing its closure, although some lanes were later re-opened.
"At times it looks like there’s fire in the sky with the wind whipping back and forth," eyewitness Ryan Marble, waiting in a long line at a gas station to get fuel to evacuate, told a newspaper.
At least 15 buildings have been destroyed, including three homes, said Michael Davis, fire chief in the seaside resort of Carlsbad, north of San Diego.
The blazes, which also closed a major north-south highway, come amid record temperatures in the western US state, where the annual wildfire season typically starts much later in the year.
But on Wednesday multiple fires erupted, including two at the Camp Pendleton base between Los Angeles and San Diego, where a naval weapons station was evacuated, along with military housing and a school.
Twenty thousand people were asked to evacuate their homes near San Diego on Tuesday night, although the order was later lifted as firefighters got the upper hand on the blaze.
The blazes, which also closed a major north-south highway, come amid record temperatures in the western US state, where the annual wildfire season typically starts much later in the year.
Thousands of people are fleeing their homes to escape raging wildfires in southern California, which on Wednesday triggered the partial evacuation of a military base and a tourist amusement park.