The string of robberies began before midnight and occurred within a 4-mile radius in the Harbor Gateway and West Carson areas, according to the Los Angeles County Sheriff's Department.
At least two men were assaulted in the hold-ups, including one who was taken to a hospital. One victim, wearing a blood-spattered sweatshirt, said he was struck in the back of the head with a handgun.
The suspects were described as a group of as many as four men wearing masks. They remained at large after fleeing in a black Kia or Scion with heavily tinted windows and no licence plate.
The total amount of money stolen was unknown.