New Zealand authorities say four people, including a child, are dead in the wake of former Tropical Cyclone Gabrielle lashing the country, with a magnitude-6.1 earthquake now also hitting the nation.
Police said the child's body was found in Eskdale the remote east coast after the youngster was "believed to have been caught in rising floodwater".
Emergency Management Minister Kieran McAnulty said a body was found at the site in Muriwai, a beach community near Auckland, where volunteer firefighter Dave van Zwanenberg went missing on Sunday night following a landslide.
Mr McAnulty said the remains of two other people were recovered in the hard-hit Hawke's Bay region.
"In the search for the missing firefighter, a body has been located," he said during an update on the country's ongoing recovery from the weather event.
"It is yet to be identified, nevertheless our deepest condolences to the family, community and of course to all volunteers and emergency services.
"This will no doubt hit hard."
It came as government seismic monitor Geonet reported a magnitude-6.1 earthquake had struck near the capital Wellington.
The earthquake's epicentre was 50 kilometres from the town of Paraparaumu and hit at a depth of 48 kilometres, according to Geonet.
There were no immediate reports of damage.
Ex-Tropical Cyclone Gabrielle, which reached New Zealand on Sunday before making its way down the east coast of the North Island, cut off entire towns, washed away farms, bridges and livestock, and inundated homes.
Authorities estimate more than 10,000 people have been displaced so far.
Helicopters winched people stuck on rooftops to safety, while military planes will be used to deliver essential supplies to isolated towns, Mr McAnulty said.
"Our immediate focus has been undertaking lifesaving missions for those affected by the floods who needed to be rescued," said Prime Minister Chris Hipkins.
"Please don't return to your homes until you have been given the all clear to do so," he said, warning that the situation remains dangerous even as the weather improves.
Hard-hit residents asked to conserve water and food
The extent of devastation is still unfolding — thousands of homes had to be evacuated and some areas are cut off by phone and road.
Police said 1,442 people had been reported uncontactable on the North Island by Wednesday afternoon.
The large number could be explained by widespread disruptions to telecommunications and power.
"As New Zealand wakes this morning, there's parts of the country who are really still in the middle of the effects," said Kerry Gregory, chief executive of Fire and Emergency New Zealand on Wednesday.
"When we look at places like in the Hawke's Bay, around Wairoa or around Napier, when we look at Tairawhiti, you know, there's communities who are right in the heart of the impacts of the cyclone."
Residents in hard-hit areas were being asked to conserve water and food because of fears of shortages.
The worst of the weather has now cleared and meteorological service WeatherWatch said in a statement that the former cyclone was east of the country and continuing to track away from the North Island, with weather now improving.
However, rivers in Hawke's Bay, a region on the eastern coast of the North Island, continue to pose risks and the local emergency management ordered further evacuations early on Wednesday.
About 144,000 properties on the North Island were without power on Wednesday, down from 225,000 on Tuesday, The New Zealand Herald reported.
Mother of four Jennie Perris, who lives on a 4-hectare block of land on the outskirts of Whangarei, north of Auckland, said the family had been without power since Sunday.
Ms Perris said the roads had cleared on Tuesday and the family had been able to head into the city and shower at her mother's house, charge devices and stock up on bottled water but it was now back to cooking on the barbecue.
"We're doing everything on it," she said.
State of emergency
As high winds and driving rain lashed the country's North Island, Prime Minister Chris Hipkins declared a national state of emergency on Tuesday.
"The impact is significant and it is widespread," he said.
"The severity and the damage that we are seeing has not been experienced in a generation."
Local media reported some people were forced to swim from their homes to safety. Others waded through stormwaters on foot. Some were forced to shelter in place.
"During the night a huge tree came down in front of our house, just missing my Ute. It blocked the road and we couldn't get out," said 53-year-old Whangamata resident Brendon Pugh.
"It's been scary, I am an ex-coastguard but I have never seen anything like it in 20 years living here," he said.
"The water in our road was up to my shins, then waist deep in places. We were without power from 10pm last night until about 3pm today and we had no internet."
More than three-quarters of New Zealand's 5 million residents live on the North Island, where the brunt of the storm was felt.
Some areas are still inaccessible by road and without power or telecommunications.
The main road between the capital Wellington and the country's largest city Auckland is closed.
New Zealand's three main mobile phone networks said a total of 455 sites were offline.
International and domestic flights were grounded, with Air New Zealand alone reporting more than 600 flights cancelled and 35,000 customers affected, although airports were gradually reopening.
The military has been deployed to help with evacuations.
'Cascading' crises
Cyclone Gabrielle formed off the north-eastern coast of Australia in the Coral Sea on February 8, before barrelling across the South Pacific.
It bore down on New Zealand's northern coast on Sunday, bringing gusts of 140 kilometres an hour.
In the next 24 hours, coastal communities were doused with 20 centimetres of rain and pounded by 11-metre waves.
Many parts of northern New Zealand were already waterlogged when the weather system hit, having been drenched by record rainfall two weeks ago.
The national MetService said Auckland Airport received 48 per cent of its annual average rainfall in 45 days.
Cape Reinga on the northern tip of the North Island recorded 30 consecutive hours of gale-force winds.
Massey University professor Christine Kenney warned that New Zealand is living in the age of "cascading" natural disasters — where the impacts of repeated severe weather events build up over time.
"Cascading natural hazard events fuelled by climate change are the new norm for Auckland," she said ahead of Tuesday's emergency.
Climate scientist Daithi Stone said Cyclone Gabrielle had been feeding off unusually warm seas, driven by a combination of climate change and La Nina weather patterns.
"Gabrielle is very much part of the story this summer of a warm nearby ocean using a warm atmosphere to pump rain onto Aotearoa," he said Tuesday, using the Maori-language name for New Zealand.
"It is also part of the global story of tropical cyclones becoming more intense under human-induced climate change."
ABC/wires
