The incident took place in a Dunedin supermarket earlier in the day. Two people among those injured were reportedly the supermarket's employees. Three victims are in critical condition and will undergo surgery later on Monday, police told reporters.
"Upon arrival, police located four people with serious stab-related injuries. We also located a man, who had been detained by members of the public, that we believe is allegedly responsible for this incident", the police said in a statement without revealing their identity, adding that the alleged offender was also hospitalised with injuries.
According to preliminary conclusions, it was a random attack. An investigation into the motives is underway.