Fire crews fully contained a small brush fire burning along the 57 Freeway in the San Dimas area Friday afternoon, according to Caltrans.
The blaze was reported around 1:15 p.m. on the southbound 57 Freeway at Via Verde Avenue, said Humberto Agurcia of the Los Angeles County Fire Department.
Video shot from the scene shortly after showed multiple pockets of fire burning brush on a hillside that bordered the freeway.
The fire burned about 1 acre by 1:30 p.m., the Fire Department tweeted. It burned about 2.5 acres before it was fully contained.
A SigAlert was issued around 1:35 p.m., and the Nos. 3 and 4 lanes on the southbound side were closed "until further notice," the California Highway Patrol tweeted.
It was unclear what sparked the blaze.
KTLA's Jennifer Thang contributed to this story.