Update: A person of interest is being sought in connection with the 100-acre blaze. Read the updated version of this story here.

Original post: A 100-acre brush fire was blazing near Running Springs in the San Bernardino National Forest Friday afternoon.

The fire, named Mount R, was 0% contained as of 6 p.m. and flames were traveling with a moderate to rapid rate of speed, according to the San Bernardino County Sheriff’s Department. The blaze was all on Forest Service land.

Sky5 was overhead as fire crews in helicopters dumped red retardant to suppress the blaze.

Mandatory evacuations were lifted to voluntary status around 8 p.m. from Running Springs School Road to south of Highway 18, and in the Fredalba neighborhood, and for everything east of Cobblestone Lane and west of Pine Manor Lane. Evacuations were also in place on Keller Peak Road, fire officials said, and in the area south of Highway 18, east of Graham Drive and west of Cobblestone Lane and  south of Canyon Court.

Highway 330 was closed in both directions from Highland Avenue to Live Oak Canyon but reopen around 8 p.m.

The cause of the fire is under investigation.