New Zealand declared a national state of emergency for only the third time in its history on Tuesday as Cyclone Gabrielle caused widespread flooding, landslides and huge ocean swells, forcing evacuations and stranding people on roof tops.
About 225,000 people were left without electricity.
"It has been a big night for New Zealanders across the country, but particularly in the upper North Island... a lot of families displaced, a lot of homes without power, extensive damage done across the country," Prime Minister Chris Hipkins told reporters after the declaration.
At 3 pm (0200 GMT) Gabrielle was around 160 km (100 miles) southeast of Auckland, near the east coast of the country's North Island, and is expected to continue moving southeast, roughly parallel to the coast. Weather warnings remain in place for much of the east coast of the North Island and upper South Island.
Kieran McAnulty, minister of emergency management, said that while New Zealand was now through the worst of the storm, more rain and high winds were expected. The country was suffering from extensive flooding, landslides and damage to roads and infrastructure, he added.
Transmission companies around the country are reporting damage to substations and power networks. Energy Minister Megan Woods said around 225,000 people were without electricity.
Authorities have evacuated beach settlements and are urging still more people to leave homes as rivers continue to swell and huge surf inundates beachfront properties.
Roads are closed, mobile phone services down and some towns cut off. Residents in hard-hit areas are being asked to conserve water and food because of fears of shortages. Air New Zealand has again cancelled all domestic flights in and out of Auckland.
Helicopter and boat crews were rescuing people trapped by rapidly rising flood water in Hawke's Bay, southeast of Auckland.
Hipkins said it was too early to say how many people had been displaced or injured. No deaths have been confirmed.
Media reported one person was missing after a house had slid down a hill in Hawke's Bay, while the fire and emergency service said a volunteer firefighter was still in a house that had been swept downhill in a landslide.
Local media published photographs and video of people sitting on top of buildings surrounded by flood water, of houses swept to the bottom of hills by landslides and of roads under water.
A New Zealand warship rescued a person from a yacht that turned on its emergency beacon this morning off the east coast.
New Zealand declared national emergencies after an earthquake in 2011 and when the Covid-19 pandemic hit in 2020.