Four people have been taken to hospitals across the South Island after separate crashes involving two buses carrying Chinese tourists.

The accidents happened about 8.40am in icy conditions, and 100m apart on State Highway 8 near Twizel.

Hato Hone St John confirmed it responded with three helicopters, three first response units, one ambulance, one rapid response vehicle and one operations manager.

One person has been flown by helicopter to Dunedin Hospital in a serious condition, one to Timaru Hospital in a serious condition, and two more patients have been taken to hospital with moderate and minor injuries.

“Multiple patients have been assessed on scene, and we are still in the process of completing assessments,” a spokesperson said.

Police said those on board were understood to be international tourists, with the relevant consulate being advised.

The Chinese Consulate General confirmed the buses were carrying Chinese tourists.

“According to the New Zealand police report, on the morning of July 18, two buses carrying Chinese tourists in New Zealand’s South Island slipped off the road,” it said.

A police cordon near the scene of two bus crashes on State Highway 8 between Tekapo and Twizel. Photo / James Allan

“Two Chinese tourists were seriously injured and have been rushed to the local hospital. No fatal injuries occurred in these two accidents.”

Chinese consular staff have “rushed to the hospital to visit those injured”.

“We would like to remind the Chinese citizens who recently come to the South Island of New Zealand that the weather in the South Island is changeable in winter, with rain and fog, slippery roads and sometimes ‘black ice’,” it said.

“Be sure to raise your safety awareness, pay attention to traffic safety, slow down when driving, and keep your seat belt fastened all the times.”

Passengers on board the buses who have not required medical attention have been taken to Twizel.

Foreign tourists are being triaged at the Twizel Events Centre after two buses crashed in icy conditions on SH8 near Tekapo. Photo / James Allan

Passengers from one of the bus crashes near Tekapo are transferred from a coach to the Twizel Events Centre for treatment and triage. Photo / Supplied

McKenzie District Mayor Anne Munro said the Twizel Events Centre has been tranformed into a makeshift triage centre to care for any passengers from the crash.

”The situation is still unfolding but it’s been fantastic to watch people step up to the situation, I’m very grateful for that,” she said.

“Our thoughts are with everyone involved, and their friends and families. We are also grateful for the work being done by the emergency services.

“Conditions are poor with ice and freezing fog – people are asked to avoid the area and drive to the conditions to avoid putting undue pressure on the emergency services.”

The Otematata Volunteer Fire Brigade truck in hoar frost conditions this morning. Photo / Otematata Volunteer Fire Brigade

Police said weather conditions were foggy at the time, however, the exact cause of the crashes is still being determined.

NZ Transport Agency Waka Kotahi (NZTA) has closed SH8 Tekapo and SH80 Lake Pukaki near the intersection with Hayman Rd.

The transport agency said there are no immediate detour routes available, and anyone needing to travel through the area should plan for the road to stay closed for the “remainder of the day”.

Police said in an earlier statement the two bus crashes happened about 100m apart.

“There are multiple injuries, the extent of which is still being confirmed.”

A photo from a passing motorist shows a bus flipped onto its side, straddling a grassy ditch.

The conditions are misty and the road surface slick. The bus has landed on top of a fence.

NZTA said drivers should allow at least two hours longer for travel times while the road remains closed.

“Westbound travellers should use SH8 east to Timaru, SH1 south to the SH82 junction, and the inland route on SH82 to Kurow/SH83 junction, with westbound to SH8/83 Otematata. Eastbound travellers should use the reverse route.”

The scene on SH8 looking south from Lake Ruataniwha Spillway Bridge, away from Twizel. Photo / NZTA

A Fire and Emergency New Zealand spokesman told the Herald 30 to 35 firefighters are at the scene, with more on the way.

“There are seven crews in attendance, from Twizel, Lake Tekapo, Ōmarama, Otematata and two from Timaru on the way,” he said.

He said at least 40 firefighters would be working once all crews arrived.

“There’s a lot of black ice down there at the moment – it is treacherous,” he said.

Hato Hone St John is also in attendance with multiple ambulance units responding to the scene.

Twizel community board member Tracy Gunn said the intersection with Hayman Rd has issues regardless of the weather conditions.

”The current conditions with the fog, low visibility and black ice is a recipe for disaster.

”That corner is just notorious for accidents. You’ve got a tourist carpark right there, so often people driving there don’t know the roads.

“Because it’s close to the water the fog and ice on the road is far worse. It’s the perfect storm for accidents”.

Gunn said as a local you know to slow down near the intersection, regardless of the conditions, “but anyone who doesn’t know the road just doesn’t know that”.

An ice warning had been in place at the time of the crash.

A staff member at Pukaki Airport, about 2km north of Twizel, said they saw an ambulance drive past at 9.05am.

They said it was -2C and foggy this morning.