Oakland policetold the Oakland Tribune most of the victims were hit in the arms and legs and that they range in age from 18 to 29 years old. Police said they think the gunman was aiming at a single person and that most of the victims were hit by stray bullets.
All were hospitalized Sunday morning with non life threatening injuries.
The shooting happened around midnight at Sweet's Ballroom on the 1900 block of Broadway.
Oakland police Lt. Rick Hassna told the newspaper that when officers arrived on the scene they found hundreds of people running out of the Fright Fest party.
So far, police haven't made any arrests.