At about 8:30 p.m., three shots were fired at two men in a Pontiac Grand Am as they drove north in the 800 block of Cypress Avenue, South San Francisco police Sgt. Bruce McPhillips said.
No one was injured, but the bullets struck a parked car and broke a window, McPhillips said.
Arriving officers saw several people running from the scene, McPhillips said.
The shooter, who was on foot, was described as a bald Hispanic man with a large build. He was wearing a T-shirt and blue jeans.
The shooting is not believed to be random, but investigators have not yet determined the motive, police said.
Anyone with information about the case is asked to call the South San Francisco Police Department at (650) 877-8900, or the anonymous tip line at (650) 952-2244.