New South Wales premier Gladys Berejiklian announced the "difficult" decision, telling the city's population of five million it was time to "bunker down"
Ardern confirmed New Zealand was dealing with the highly transmissible Delta variant linked to the outbreak in Australia that authorities have so far been unable to contain
Four of the five people that died were unvaccinated while one had at least one dose, New South Wales state health authorities said, as they implored residents to get inoculated as early as possible