A 36-year-old man has been charged with murder following the stabbing incident in central Whanganui on Tuesday.
The man will appear in Whanganui District Court on Wednesday afternoon where he also faces five charges of wounding with intent to cause grievous bodily harm.
One person died and five others were injured following the incident in Wicksteed St in central Whanganui just after 4pm on Tuesday.
Police launched a homicide investigation later that evening after taking one person into custody.
Speaking to media on Wednesday afternoon Whanganui Police area commander Nigel Allen said it had been a "traumatic incident for all involved".
"Along with victim support we're working hard to support the victims, their whānau and our staff," he said.
"We acknowledge this incident has the potential to be unsettling for our community and I want to reassure the residents that we are not looking for anyone else in relation to this matter.
"We are absolutely committed to ensuring that people in Whanganui are safe and feel safe and I can assure the community there is no ongoing risk to the public as a result of this incident."
Allan said because the matter was before the court he would not comment further on the incident or charges.
He said the incident "was dynamic to say the least".
Our staff who attended had a lot to deal with in a short space of time," Allan said.
"We absolutely appreciate the support of the public, particularly staff from Te Oranganui and staff from the medical centre there who've helped the victims.
"Not being there, but listening to the event [I'm] extraordinarily proud of our staff and how they managed their role there. Difficult scene, obviously you know where it is, it's a public place, so we got control of that scene and provided assistance to the victims as soon as we practically could.
"It's a tragic event.
The Whanganui Chronicle understands the incident stemmed from a dispute between two flats.
A source said the incident arose from an argument over "something relatively minor" between two flats who share the duplex on Wicksteed St.
This morning, a Whanganui DHB spokesman said two of the five injured had already been discharged.
Those remaining were a woman in her 20s, another woman in her 30s and a man in his 50s. They were all in a stable condition, the spokesman said.
The cordon was centred around a residential property on the street.
A worker from medical centre Te Oranganui, who did not want to be named, said a colleague witnessed the stabbings.
Te Oranganui nurses and a doctor ran to the aid of the victims.
"When I got there, there was one lying on the ground. It was a big girl. She'd been stabbed, it was bad."
The worker said two other people who had been stabbed were walking around.
"You could see it. He was holding his neck and blood was pouring out. On his back, you could see where he'd been cut.
"There was another lying down, she wasn't moving. She was an older lady."
The worker believed the stabbing victims were four members of one family.
Blood was splattered across the New World carpark.
There were three upturned supermarket trolleys within the carpark cordon yesterday.
A St John spokeswoman told Stuff two people had been taken to Whanganui Hospital in a critical condition while a further two were in a moderate condition.
Another witness told Stuff he was putting groceries into his car when he heard cries for help.
"She had severe facial and arm lacerations, and told us she and others were attacked by a man with a knife on the corner of Wicksteed and Liverpool streets."
He helped comfort her until emergency services arrived.
During that time another man approached from Liverpool St with a stab wound to his neck and told those gathered there was another woman who was badly injured.
Emergency services were called to the incident at 4.20pm, a police spokeswoman told the Herald.
An ambulance is in attendance and police are speaking to nearby residents, the police spokeswoman said.
Baskett said one person was taken into custody immediately after the incident and police were not looking for anyone else in relation to the matter.
The cordon on Wicksteed St and Liverpool St would remain in place overnight.
Officers remained at the scene.