MALIBU, Calif. (CNS) — At least 150 firefighters extinguished a six-acre brush fire in a remote area of Malibu Friday morning and were expected to remain on site most of the day to guard against lingering hot spots.

The fire located off Tuna Canyon Road was 50% and was surrounded by a line of cleared vegetation just before 10:30 a.m., but it was no longer spreading and the flames were out, Los Angeles County Fire Department officials reported.

Firefighters may spend the entire day making sure there are no hot spots to rekindle the flames, which were in a difficult place, L.A. County Fire Department Dispatch Supervisor Imy McBride said.

The blaze, first reported at 12:46 a.m., "has presented access challenges," with firefighters having to hike approximately 2,000 feet via a narrow trail and in steep, rugged terrain to get to the burning area with their hoses, fire officials said. The location of the blaze was about one mile up Tuna Canyon Road from Pacific Coast Highway.

Three water-dropping helicopters helped fight the fire from above but were no longer in use, McBride said.

No structures were threatened and no injuries were reported, fire officials said.

The California Highway Patrol issued a SigAlert, shutting down Tuna Canyon Road from Las Flores Heights Road to PCH.