A coronavirus case that plunged New Zealand into a snap national lockdown was confirmed as the Delta variant Wednesday, Prime Minister Jacinda Ardern said, as four more cases emerged.
Ardern said one of the new cases was a nurse at Auckland Hospital, which had been placed in "internal lockdown" while all staff and patients were tested.
The prime minister said the spread of the virus justified her decision to issue nationwide stay-at-home orders on Tuesday after the initial case was identified.
"It demonstrates, at this stage, level 4 (hard lockdown) is the right place to be," Ardern told TVNZ.
The first case, a 58-year-old Auckland man, ended a six-month run without community transmission in New Zealand, which has recorded only 26 Covid-19 deaths in a population of five million since the start of the global pandemic.
The initial plan is for New Zealand to remain in lockdown for three days, with Auckland and the nearby Coromandel area facing restrictions for a week.
Ardern said the country's strategy of eliminating the virus, rather than just containing it, had worked throughout the crisis and she was confident it would succeed against the highly transmissible Delta strain.
"Yes, Delta poses a greater threat, but the same tools that have worked before will do so again if we follow the rules," she said.
She said wastewater testing in Auckland had detected no sign of the virus, giving cause for optimism.
"That tells us that, if we have something, it doesn't appear to be a long-standing outbreak because we haven't had anything in our wastewater testing," she said.
Officials have said the latest outbreak has no obvious connections to the border, and investigations to determine its origin are ongoing. (AFP)