"Homes are not directly in the line of fire," county fire spokeswoman Angie Samayoa said early Wednesday morning.
Investigators said the blaze was sparked by fireworks.
At 11 a.m., firefighters said the fire was 60-percent contained. Fire officials said full containment was expected Wednesday evening.
People in about 100 homes near a Buddhist temple were told they may want to evacuate but were not ordered to do so, Samayoa said.
About 350 firefighters were on the scene and aircraft dropped water on the flames, Samayoa said.
"It sounds like they're holding it ... it doesn't seem to be progressing so far," she said.
There were no reports of any smoke or fire near the freeways and no word of any injuries, officials said.
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The fire broke out five years to the day after the beginning of the Grand Prix wildfire, which burned 59,000 acres and destroyed 135 homes in the same area, officials said.
Strong Santa Ana winds returned one week after similar conditions spurred several major wildfires. The dry northeast winds were expected to peak at 50 mph through Wednesday evening -- weaker than last week's siege.
Temperatures were expected to reach the 90s in many areas.
Because of hot and gusty conditions in that area of San Bernardino County, east of Los Angeles, a red flag warning signifying a high risk of wildfire was in effect until 11 p.m. Friday.
Porter Ranch Fire Breaks Out in Burn Area
Firefighters on Wednesday morning extinguished a smoldering fire that erupted in debris left behind in the area recently burned by the 14,735-acre Porter Ranch blaze.
No structures were threatened or damaged.
The fire was reported at about 7:15 a.m. at the bottom of a canyon near the 11400 block of Browns Canyon Road, said Brian Humphrey of the Los Angeles Fire Department. The area is near the Ronald Reagan (118) Freeway, about five miles
southwest of the general area where the Sesnon fire began on Oct. 13.
"There was a large mass of smoldering debris," said Humphrey, adding that firefighters backed by helicopters doused the flames in about an hour and 15 minutes.
Last week's blaze, which took several days to extinguish, was sparked in an unincorporated area near Porter Ranch when heavy winds blew down a power line that fell onto dry brush. The line is owned by the Southern California Gas Co.
The blaze burned across the Los Angeles-Ventura county line, fanned by strong Santa Ana winds. Dozens of homes and outbuildings were damaged or destroyed, and one death was connected to the fire. A man crashed his vehicle on the 118 Freeway just hours after the fire began, when he apparently became confused by the heavy smoke.