Firefighters investigate grass fire along Highway 99 in Fresno as possible arson

FRESNO, Calif. (KFSN) -- Firefighters are investigating a series of fires near Highway 99 in downtown Fresno.

The fire sparked near Ventura Avenue around 9 a.m. on Thursday

Fire crews believe the grass fire was started by an arsonist, and say the suspect is still in the area. It wasn't immediately clear if a person was in custody.

The California Highway Patrol closed the Ventura on-ramp to drivers as firefighters dealt with the flames.

This is a developing story. Stay with Action News for updates.