The fast-moving Silver fire in Riverside County has now consumed 14,000 acres and is 20% contained, authorities said Thursday night.
The brush fire started Wednesday afternoon south of Banning and grew quickly, burning more than 1,000 acres per hour.
At least five people have been injured: four firefighters and one man who suffered burns from head to toe. More than 1,400 personnel are working to stop the blaze.
Mandatory evacuations have been issued for the communities of Snow Creek, Black Mountain, Vista Grande, Mt. Edna, Poppet Flats, Silent Valley, portions of Cabazon and Twin Pines.
About 4:15 p.m. Thursday, CalFire said the blaze continued "to be active on the eastern flank toward the Cabazon area."
"The Silver fire ... is burning uncontrolled in the foothills below Black Mountain," CalFire said on its website. "Black Mountain has been evacuated and closed as a precaution."