Police sergeant John Sheahan said five vehicles were involved, including a taxi that burst into flames and killed two people at a busy junction.
He said people in a Maserati and a Range Rover Sport were exchanging gunfire before the Maserati hit the taxi.
The Maserati driver, the taxi driver and a taxi passenger were killed in the incident.
Three other vehicles were involved in the wreck, but Sgt Sheahan said the Range Rover, which was said to have large black wheel rims, was gone by the time police arrived at the scene.
At least three people were taken to hospital, including a passenger from the Maserati.
The crash site was at an intersection near the famous Bellagio and Caesars Palace hotels, in the heart of the Strip and the injured were taken to the University Medical Centre hospital.
It is the third incident of violent crime to hit the popular Nevada casino resort this month.
Two people were wounded in a shooting at a Las Vegas car park on February 6 and a tourist was stabbed in a lift at the Hotel Mandalay Bay on February 16.