Multiple stabbings at Dunedin supermarket, three critically injured, one person in custody

A man is apprehended after a stabbing attack in Countdown Central in Dunedin today. Photo / Otago Daily Times/ Supplied

Brave shoppers tried to tackle and subdue a person armed with a knife who stabbed several people in a Dunedin supermarket.

Four people are injured - three critically - as shoppers watched in horror as a multiple stabbing took place in the store.

St John ambulance say four patients have been rushed to hospital. Three people are in a critical condition and one is serious.

Prime Minister Jacinda Ardern said at this stage there was nothing to suggest a domestic terror event.

Police's early assessment is that was not the case, she said.

"Needless to say such an attack is hugely concerning," she told reporters at her post-Cabinet press conference.

Ardern acknowledged courageous efforts by bystanders, and said thoughts were with all those injured.

Police had some indications of underlying factors that may have contributed, Ardern said.

She did not feel comfortable sharing those yet.

One person is taken on a stretcher to a waiting ambulance. Photo / Jacob Kendall

Countdown has confirmed two staff are among the injured.

Police have confirmed one person has been taken into custody at the Countdown supermarket in Cumberland St.

A witness says he could see people being wheeled out on stretchers, covered in sheets.

"They were alive," he said.

The man's wife said she saw "someone being dragged out by police, bloody, out onto the street".

'Chaos': Shoppers tackled alleged stabber

A couple, who asked not to be named, were shopping in the aisle next to the pharmacy department, where the incident took place.

"We just heard a scream and thought someone must've fallen, but it got louder and louder and more people were screaming," the woman said.

"I saw one red hand among the people; a bloody hand, and everybody started running towards the exits."

The man said brave members of the public had pinned down the stabber but they believed he had been able to wrestle his way free before police arrived.

One woman who was shopping a couple of aisles over, said she was also alerted to the incident by the high-pitched yelling.

"I heard screaming and I thought it was just teenagers, but then I heard someone yell 'he's got a knife'."

A man is apprehended after a stabbing attack in Countdown Central in Dunedin today. Photo / Otago Daily Times/ Supplied

Another woman who was entering the supermarket at the time said she was confronted by two hysterical girls.

Another bystander grabbed them, thinking they were shoplifters but they were followed by a stampede of shoppers.

"It was chaos," she said. "Unbelievable."

Worker emerged "in a hell of a state"

Jailhouse lawyer Arthur Taylor was one of the first people on the scene.

He told the Herald he'd just walked into the supermarket car-park when a police car came flashing past him.

"It must have just happened because he was the first police car there," Taylor said.

More police cars and ambulances turned up before he saw police officers walking a man out of the store, in handcuffs, with blood on him.

Taylor thought he looked like a "raving lunatic".

He then saw two people brought out on stretchers and put into ambulances.

A Countdown worker emerged "in a hell of a state", said Taylor who sat with him and tried to calm him down.

"He must've witnessed it all. He was sweating, couldn't string many words together at all," said Taylor.

Taylor got the impression from the rattled employee that the incident might've been a "robbery gone wrong".

"I quite often go into that supermarket, and you couldn't get better staff."

'Shocked and devastated'

Spencer Sonn, Countdown managing director, said they were "shocked and devastated".

"Our priority right now is our injured team members and caring for our wider team in the wake of this extremely traumatic event. We are deeply upset that customers who tried to help our team members were also injured.

"We have been concerned about the escalating violence towards our team, and this is something we have continued to talk and raise as an issue over the last year.

"Our amazing team comes to work to serve Kiwis every day, and our customers visit our stores knowing that they will be safe. We are heartbroken that this wasn't the case today.

"Our Dunedin Central store will remain closed today and tomorrow while we support our team, and we are co-operating fully with the police."

Staff included among injured: witness

An Otago Daily Times reporter at the scene said one person was put into an ambulance with an apparent neck wound.

A second person has been seen stretchered into an ambulance.

At least one of the patients is a member of staff and more are expected to come out.

Police said initial information suggested "several people have been injured".

A third person wearing a Countdown uniform has come out with a bandaged shoulder.

A fourth injured person who also appeared to be a staff member was taken out of the supermarket with what looked like head and shoulder injuries.

Police have blocked the entrances to the carpark but some people are being allowed to leave the carpark.

People can be seen crying and hugging each other.

Emergency services at the scene after reports of multiple stabbings. Photo / Craig Baxter

A person at the scene said a staff member told him two other staff members had been stabbed and that the attacker allegedly walked up to someone and stabbed them in the back.

A man, who was seen covered in blood, has been apprehended by police at about 2.35pm.

There are at least two ambulances, police vehicles and armed police officers at the scene.

A witness said she was at the checkout when she heard someone else say someone "had a knife".

Armed police can be seen at the supermarket. Photo / Jacob Kendall

She said she heard people screaming.

People then began running out, she said.

Other witnesses said they saw people covered in blood.

People were seen running to help people in the supermarket.

The supermarket has been evacuated and people have been told to stay away from the windows.

A Twitter user who appeared to be in the Countdown said he saw someone who was handcuffed and bleeding as he was being removed from the supermarket.

He also saw stretchers being wheeled inside.

NZME's Rowena Duncum is at the scene, which is next door to a police station.

"The hospital is literally just two blocks away as well," she said.

"There are quite a few people who are around the outside of the Countdown car park. This is also where the buses congregate in central Dunedin. There are at least seven of eight bus stops situated adjacent to the car park.

"This is a really busy area, especially at this time of the day. As the afternoon progresses you'll start to see school children making their way here, it's a hub for them as they change buses from school."