Three people are dead after an "incredibly confronting" crash on State Highway 8 at Pūkaki in Canterbury.
Police say emergency services were alerted to the crash at about 1:30pm on Saturday.
The crash involved two vehicles and a motorcycle and happened between Hayman Road and Tekapo Canal Road.
They later confirmed three people have died. One was riding a motorcycle while the two others were travelling together in one of the cars.
"Despite the best efforts of those first at the scene, three people were unable to be saved," a police spokesperson said.
"Several of the injured were trapped in the wreckage and needed to be cut out."
St John told Newshub it sent multiple resources, including three ambulances and four helicopters, to the scene.
Three people in a serious condition went by helicopter to Christchurch Hospital, while two in a moderate condition went to Timaru Hospital by road.
A police spokesperson said they are in the early stages of the investigation to determine what caused this tragic event.
"The serious crash unit is at the scene and their work will continue into the evening. A complex and lengthy investigation lies ahead of us," they said.
"Crashes of this nature are incredibly confronting, and we are arranging support for those members of the public who were first at the scene and tried their best to save lives.
"Any fatal crash, but particularly one where multiple people have lost their lives, is confronting even for veteran emergency service personnel.
"We will also be making sure our staff at the scene have the support they need following this horrific event."
State Highway 8 will remain closed for some time yet and is not expected to reopen until late this evening.
"An alt route via SH8, SH1, SH82, SH83 and back onto SH8 is available," the NZ Transport Agency said.
Motorists are asked to delay travel or expect delays.
Only 90 minutes after this crash, Police were alerted to a second three-vehicle crash a short distance away, at the intersection of State Highway 8 and Tekapo-Twizel Road.
One person received serious injuries and nine others suffered minor-to-moderate injuries.
Enquiries into this second crash are ongoing.
"We want to ask every motorist on the roads this weekend to take extra care," police said.
"Please take your time, have plenty of breaks and drive to the conditions. Crashes like this show how easy it is for things to go horribly wrong."
