Police say they received a call shortly after noon Friday and found three male victims with gunshot wounds.
Police say subjects may have been fighting with another person before the shootings occurred. The victims' identities were not immediately released. A motive wasn't clear.
The Oakland Tribune reports (http://bayareane.ws/1Loie4h) that witnesses told police the gunman ran away. The newspaper says three ambulances were called to the scene.
The Warriors defeated the Cleveland Cavaliers in six games Tuesday, taking its first basketball championship in 40 years. Police estimate nearly 1 million people attended the parade and rally that followed.
The shootings occurred outside the boundaries of the secured rally site.
Police remain on site, trying to find witnesses.