The man entered three Chinese restaurants in Auckland and attacked diners at random, with four people taken to hospital.
Three victims remain in hospital in stable condition, while a fourth was discharged, spokespeople for the North Shore and Auckland hospitals said on Tuesday.
Local media reported that the man went into three Chinese restaurants – Zhangliang Malatang, Yue’s Dumpling Kitchen and Maya Hotpot – in the north Auckland suburb of Albany – and started randomly attacking people with an axe at about 9pm on Monday (09:00 GMT).
Police said a 24-year-old suspect was arrested at the scene and later charged with wounding with the intention of causing grievous bodily harm. The man, a Chinese national, made a brief appearance in court on Tuesday.
Inspector Stefan Sagar, the Waitemata East Area Commander, acknowledged “how frightening this was for those involved”.
He said police believe it was an isolated incident, adding that there was no evidence “to suggest this is a racially-motivated attack”.
A diner told the New Zealand Herald newspaper he was eating dinner with a friend when the man walked in and started attacking his friend, who was seriously wounded.
“I was in shock. When I realised what was happening, he tried to target me,” the man, who asked not to be named, told the Herald. “I blocked his axe with my hand. He was also trying to target my head, so I blocked the axe with my hand.”
The diner said the man with the axe chased them out of the restaurant and then turned around and walked into another restaurant.
The Herald posted an image of what appeared to be a wood-splitter-style axe lying on the sidewalk.
Surveillance footage posted by news website Stuff showed people fleeing from one of the restaurants, including one person who escaped backwards holding a chair as a barricade, followed closely by another person holding a weapon.
Police said they expect to file more charges against the man, who they believe acted alone.
During his court appearance, the suspect was helped by a Chinese language interpreter.
He was not required to enter a plea. He was granted temporary name suppression, a common outcome in New Zealand’s legal system.