Investigation underway after fire in Oakland/Berkeley Hills on Grizzly Peak Blvd.

BERKELEY, Calif. (KGO) -- Crews have put out a fire that burned two acres in the Oakland/Berkeley Hills above the UC Berkeley campus on Monday night.

Fire engines from Oakland, Berkeley and Contra Costa County were sent to Centennial Dr. and Grizzly Peak Blvd. just after 9:30 p.m.

Firefighters say no one was injured nor any structures threatened.

MORE: Extreme heat, fireworks pose high fire danger in East Bay this week

It is not clear what sparked the fire, however, ABC7 News crews found what appears to be a box of fireworks on the side of the road.

Firefighters say they received an initial tip of illegal fireworks going off in the area, but did not locate anyone.

The cause of the fire cause under investigation.