LA City Fire Department spokeswoman Melissa Kelley says the fire broke out about 10:30 p.m. at a park in Sylmar and quickly spread to 100 acres in an hour.
Television foot shows embers flying in the dark and several homes engulfed in flames.
Kelley says a mandatory evacuation has not been ordered, but an evacuation center has been set up at a nearby high school.
A National Weather Service meteorologist says a wind gust was clocked at 61 miles per hour in the fire area.
The cause of the fire is under investigation. No injuries have been reported.