Las Vegas police Lt Jay Roberts said a suspect is in custody. The victims were taken to University Medical Center, although the conditions of the injured people were not immediately available.
Roberts says the shooting happened about 5:45 am today local time at Drai's, an afterhours club that caters to those who have wrapped up their nights at other hotspots.
It's located in the lower level of Bally's.
The Strip was the scene of a dramatic shooting and explosion just this past winter. Authorities say verbal sparring erupted into a shooting, chase and crash that left three dead in February. A death penalty trial is set for December 2 against a man who once bragged about his lifestyle as a pimp.