Two people have been choppered to hospital in a serious condition after a bus rolled near Queenstown, blocking the road and leaving 20 people injured.
Two others passengers on the bus were taken to hospital to be treated for less serious injuries, Inspector Olaf Jensen, Otago Lakes Area Commander said.
The Glenorchy-Queenstown Road was closed while heavy lifting equipment moved the tipped bus but reopened just after 8pm.
The crash occurred on Glenorchy-Queenstown Rd about 7km southwest of Queenstown. The bus came to rest on its side.
More than 20 people had been on the bus, all foreign nationals, Jensen said.
"I want to highlight the good work by the members of the public who were first responders on the scene, who helped those involved until emergency services arrived."
Passengers on the crashed bus were speaking to police, and both the Serious Crash Unit and the Commercial Vehicle Safety Team advised of the accident.
Investigations into the crash are ongoing.
A local resident described seeing the walking wounded at the scene being cared for by St John ambulance staff.
She told the Otago Daily Times the bus and a luggage trailer had flipped on to its side and blocked both sides of the road.
The windscreen was smashed, but that could have possibly been done by rescuers.
"It doesn't actually look that damaged," she said.
The crash happened on a "very sharp" bend where there had been crashes before, but they mostly happened in winter.
She did not get close enough to see the seriously injured passengers, but had seen a helicopter land.
The woman praised the work of emergency services staff and said the scene was remarkably calm given the seriousness of the crash.
A St John spokesman said ambulance officers had treated 20 people - two with serious injuries, one with moderate injuries and the remainder with minor injuries.
"We are still on scene and the patients will be transported to Dunedin and Lakes District Hospitals," he said earlier.
Two helicopters had been sent.
Three ambulances had been at the scene, accompanied by a manager.