It cut a three-mile path across the city, tearing off roofs and uprooting trees.
The tornado first touched down in Albany and then passed through neighboring Birkenhead. Most of the serious damage was in Albany, where a shopping mall, a large hardware store and a supermarket were hit. Radio New Zealand reported that the roof of the Mega Center mall in Albany collapsed.
Tornadoes are not uncommon in New Zealand, but they tend to be smaller than those seen in the U.S.
New Zealand has been hit by several disasters in recent months, including the earthquake in February that hit Christchurch and killed 169 people.
The Associated Press contributed to this report.
