Firefighters knocked down a mulch fire that broke out along the 118 Freeway in Porter Ranch on Tuesday afternoon.
The fire was fueled by wood chips used in landscaping next to the freeway shoulder at Reseda Boulevard, said Los Angeles Fire Department spokesman Brian Humphrey.
No structures were threatened and there were no evacuations, Humphrey said.
Live video from the scene showed white smoke drifting away from freeway lanes. Click here for a real-time traffic map.
Witnesses told police the fire may have been deliberately set by someone driving a black SUV, LAPD Capt. Robert Marino said.