Two people are dead after a fiery crash between a rental car and a bus carrying 16 tourists on the Te Anau-Milford Highway in Southland yesterday.

Southern Area Commander, Inspector Joel Lamb, said this morning witnesses had told police there were two people in the car.

"Police are working to identify all individuals in the vehicle but can confirm there were no survivors from that vehicle.

Due to the damage to the vehicle it will take the Police Disaster Victim Identification Team some time to positively identify any individuals in the vehicle."

Everyone from the bus got out safely, with several needing first aid at the scene and later at a medical centre, Lamb said.

Police, fire and ambulance worked together to secure the scene to put out the fire, treat the wounded and assist those affected by the crash.

The scene was cleared late last night.

"This is a horrific incident that has impacted a large amount of people and that of the Te Anau and Milford communities."

Police were working with Victim Support and wider groups to provide assistance and support for those involved in the crash.

They thanked everyone who stopped to help and urged anyone involved to contact the Southern District Command Centre on (03) 471 5002. 

Earlier, a witness described horrific scenes following the crash.

A man lay trapped, screaming for help in the crushed wreck of the car after the collision on the popular tourist route.

Minutes later, the car burst into flames, with the man still inside.

Police said yesterday no one could be pulled from the car and, aside from the man pleading for help, they did not know how many others were inside.

Photos from the scene show the car was overturned and completely crushed by the bus.

The bus door was wedged shut and the 16 passengers, all believed to be from Korea, were helped out of a window.

Later photos show plumes of thick black smoke billowing into the sky, with the bus and car completely engulfed in flames.

Invercargill's Jakob Frazer, 17, arrived with a colleague moments after the crash happened.

He said he saw an arm coming out of the passenger door, and a man was screaming for help.

He helped those around him before trying to help the car's driver. Frazer believed the occupant was male and that he may have been foreign, as he had an accent.

When he arrived the car and bus were not on fire.

But after about 10 minutes smoke started coming from the car. Attempts to put out the fire with an extinguisher were unsuccessful and within minutes car and bus were in flames, he said.

The road reopened last night.

Fire Service southern communications centre shift manager Riwai Grace said police, ambulance staff and firefighters from the Te Anau brigade helped at the scene, he said. 

The crash happened on State Highway 94, Te Anau Downs, at 2.55pm.

Police said the injured were taken to a medical centre in Te Anau and the bus passengers were picked up by other coach operators.

Explorer Tourlines owner Stephen Cook confirmed one of his buses was involved in the crash and said all 16 passengers plus the tour guide and driver had made it off safely.

The tourists were from Korea. The bus was returning to Queenstown from Milford Sound when the crash happened.

The driver had been with the company for four years. Cook was unable to comment on what caused the crash.

"The matter is in the hands of police now. As it develops we will know what happens, but we don't actually know what happened.

"I'm sorry we just don't have any information - it's a very recent occurrence."

Cook could not be contacted for an update this morning.

Te Anau Volunteer Fire Brigade chief fire officer Graeme Moffat said the crash scene was 32 kilometres from Te Anau and the fire was "well-involved" by the time they reached wreckage.

After putting out the fire the serious crash unit did their investigation after which the fire service helped with the removal of the wreckage last night.

A crane and flatbed truck came from Invercargill to transport the wrecked bus and car, Moffat said.

It was a long day for everyone affected, from the firefighters to travellers delayed by the crash.

"There was about 500 vehicles backed up ... towards Milford."