All 17 passengers on the bus including the driver and tour guide have been removed from the scene.
Three patients have been transported by helicopter to Dunedin Hospital, two with serious injuries, and one with moderate injuries.
Another two patients have been transported to Invercargill Hospital with moderate injuries.
The rest of the passengers all received minor to moderate injuries and were transferred by bus to the Te Anau medical centre.
The westbound lane is currently open, stop-go traffic management is in place.
Police estimate the road will be re-opened in the next three hours.
The Commercial Vehicle Safety Team is at the scene as well as the Serious Crash Unit, and Police Photography.
ENDS
Issued by Police Media Centre