The car mounted the kerb at the corner of Eden St and Thames St on January 11.

A 67-year-old man is dead and five others injured after an elderly driver mounted a kerb at speed and crashed into three pedestrians and then two cars outside a popular Oamaru cafe.

Screams pierced the air outside the Lagonda Milk Bar, on the corner of Eden St and Thames St, about 11.30am on Monday, but the trail of destruction could have been even worse if the driver had not come to a halt when he hit the cars, witnesses said.

Police said the injured were:

LEE JAMIESON A man is dead after in incident on Thames St in Oamaru.

- A 70-year-old woman, a pedestrian on the footpath who suffered multiple injuries and was transported to Dunedin Hospital.

- A 13-year-old girl who was treated at Oamaru Hospital. Witnesses said her foot was run over.

- The three drivers of the cars, ages not yet confirmed, who were all taken to Oamaru Hospital for treatment.

Christchurch man Nigel Newman was on the footpath at the time of the crash and said the driver of the out-of-control car, a green Honda Jazz, had left the public toilets on Eden St and pulled out of his carpark smoothly before losing control.

"He was motoring. He was doing well and truly more than the speed limit when he went up onto the kerb," Newman said.

"He hit a bakery sign and an elderly woman first and then an elderly man. They just went flying.

"There was nowhere for them to go, it all happened so quickly."

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Police said State Highway 1 had been reduced to one lane. A serious crash investigation had been launched. They asked those with information to contact Oamaru Police.

"Police would like to thank members of the public who came to assist all the injured people."

Newman, who was on a day-trip to Oamaru with his wife, said he rushed to the elderly man who was "out cold" and bleeding from his mouth.

He helped to place him in the recovery position as two fire engines, two ambulances and four police cars rushed to the scene.

The man appeared to still be alive, but unresponsive, Newman said. Medical personnel were unable to revive him.

Newman said after the Jazz hit the pedestrian it continued through the Thames St lights and crashed into a dark grey Mazda and a white Toyota Camry, the impact of which was enough to bring it to a stop.

"It seems like he had a [medical] turn as he pulled out," Newman said. "The only thing that saved him was hitting those two cars.

"If he had kept driving through the intersection he would have gone into a concrete building at speed on the other side."

Jude Blair, who works in administration and sales support at the Waitaki Herald building, said she dialled for emergency services as soon as she heard the first of several bangs.

"I heard the first bang and then there were screams. They weren't normal screams," Blair said.

There were two more bangs as the car hit the Mazda and the Camry, Blair said.

She raced outside with other staff members at the Waitaki Herald where they helped check on the injured and direct traffic until police and ambulance staff arrived.

"There's a lot of traumatised people right now," she said.

"I was one of many out there. The community was brilliant in their response and the emergency services were fantastic too."

Another bystander, who did not want to be named, said the car seemed to be jammed in gear.