According to the Orange County Fire Authority (OCFA), the wildfire coded Aliso Fire burned in heavy brush in Wood Canyon and scorched to 200 acres (0.8 square km), four hours after it was first reported as a 25-acre (0.1 square km) brush fire.
The OCFA issued an evacuation order to about 2,000 homes nearby, Xinhua news agency reported.
At least 275 firefighters, four helicopters and two fixed-wing aircraft were involved in the firefight, the OCFA tweeted Saturday afternoon, adding so far zero percent of the fire was contained.
OCFA Capt. Tony Bommarito was quoted by the local ABC news channel as saying that the wind shifted multiple times throughout the firefight, which caused several spot fires and difficulty for fire crews.
There were no immediate reports of injuries or structural damage.