The shooting was reported at about 2:45 a.m. at a warehouse at 3499 Chestnut St. that was being operated as an unlicensed after-hours club, Oakland police spokesman Jeff Thomason said.
Emergency personnel pronounced the two men dead at the scene, and transported a woman to an area hospital in critical condition, according to Thomason.
Local hospitals later notified police that three additional women injured in the shooting had also arrived, Thomason said. Those three women are expected to survive, he said.
The motive for the shooting remains under investigation. Anyone with information is asked to call the Oakland Police Department Homicide Section at (510) 238-3821.