An AC Transit bus driver in Oakland suffered cuts after a stray bullet struck his side window Sunday night, police said.
The incident happened on Foothill Boulevard near Havenscourt Boulevard.
Investigators were trying to determine if people in two cars were shooting at each other or if the gunfire came from just one car.
Two passengers on the bus were not injured.
Get a weekly recap of the latest San Francisco Bay Area housing news. >Sign up for NBC Bay Area’s Housing Deconstructed newsletter.