According to the Los Angeles County Fire Department, the blaze has grown to 400 acres.
Authorities said the blaze began as a trailer fire that spread to brush in the 32000 block of Wagon Wheel Road just after 1 p.m.
One firefighter injury was reported, as well as one civilian injury. No details were released on the injuries.
About 250 firefighters have responded to the scene, along with five helicopters and two fixed-wing aircrafts.
DEVELOPING: We will add more details to this report as they become available.
KABC-TV LOS ANGELES, CA contributed to this report.