TUJUNGA, Calif. -- Fire helicopters briefly battled an early-morning flare-up Saturday at a brush fire that earlier had scorched nearly 15 acres near La Tuna Canyon Park in Tujunga, a city fire official said.

Choppers were dropping water on the east flank of the fire at 8:20 a.m., where the flare-up broke out. Firefighters at the scene said they had the new flames under control, but would use the water drops to help finish the job.

Unconfirmed radio reports from the scene indicated that the brief flare-up was extinguished at 8:35 a.m., and fire helicopters were concentrating water drops on possible smoldering hot spots.

The fire, along the 8300 block of La Tuna Canyon Road, started about 6:30 p.m. Friday and, three hours later, had burned nearly 15 acres, she said.

No structures were damaged or threatened by the blaze, she said.

Overnight Saturday, firefighters said they had the weather on their side.

"The cooler temps and onshore flow with moisture helps the fire burn a lot slower," said d'Lisa Davies at the Los Angeles Fire Department late Friday.

Operations were shut down for the night, but after sunrise new flames were observed and fought.

Davies said fresh firefighters would be deployed early Saturday to "finish cold-trailing ... scraping everything to bare earth,"

Some firefighters were exposed to poison oak, but no injuries were reported, Davies said.

How the fire started was unknown.