Houses have collapsed in major landslides in one of the worst-hit areas of Auckland as ex-Cyclone Gabrielle pummelled New Zealand’s North Island.

The coastal suburb of Muriwai was declared a danger zone with an exclusion area established after at least one property was destroyed.

A volunteer firefighter remained missing after he went to investigate a flooded house there on Monday night and a landslide crushed the property, the New Zealand Herald reports.

Another volunteer firefighter was rescued from the debris. The search for the missing man – identified as local veterinarian Dave van Zwananberg – had to called off due to the dangerous conditions.

“To the families of the volunteer firefighters who responded to events in Muriwai last night, and to the wider Fire and Emergency New Zealand family, our thoughts and hopes are with all of you,” Prime Minister Chris Hipkins said in his latest national update on the storm fallout on Tuesday afternoon.

Rescue operations were underway in the Hawkes Bay, on the east coast of the North Island, late on Tuesday to rescue people stranded on roofs and others stuck in vehicles.

Mr Hipkins said Gabrielle had caused damage to New Zealand “not seen in a generation” – since Cyclone Bola hit similar parts of the country in 1988.

“The centre of the cyclone is just north of the East Cape. It’s moving in a south-easterly direction away from the country,” he said.

Weather was expected to ease later on Tuesday.

“I want to acknowledge that many communities particularly in the upper and eastern parts of the North Island, that have borne the brunt of the latest cyclone and the previous one,” Mr Hipkins said.

“I know that there are people in other parts of the country and overseas, trying to get hold of loved ones who are now cut off without reception.”

He also urged Kiwis desperate to stock their pantries to only buy what they needed at supermarkets, amid reports some shelves had been stripped by panic buying. More than 40 supermarkets are shut, mostly in the hardest hit areas of Northland, Hawkes Bay and Gisborne.

Mr Hipkins said there was enough stock, but getting it to shops could be difficult.

“Please avoid all non essential travel, stay at home if you can and as long as it is safe for you to do that,” he said.

Across New Zealand, Fire and Emergency recorded 1842 incidents related to the cyclone in 24 hours, and 200 Defence Force personnel had been deployed.

Water gushes from a storm drain access port in Te Awanga, near Auckland. Photo: AAP

One of the country’s biggest power companies, Transpower has declared a grid emergency, and 225,000 customers are without power. The company said it could be days, or even weeks, before electricity is restored.

Towns have been cut off by gigantic landslides and flooded roads and badly inundated as much of the country was battered by the “unprecedented storm”. In some areas, stranded locals were plucked from rooftops.

With wild winds still battering the country, Air New Zealand again cancelled flights in and out of Auckland.

“It would be unsafe for our people to continue to operate in these conditions,” the airline said.

Auckland Airport went further, announcing the temporary suspension of all international and domestic operations “due to the high wind conditions and the need to protect the safety of workers out on the airfield”.

The shocking impact of ex-Cyclone Gabrielle triggered a national state of emergency on Tuesday morning. 

It also forced the deferral of parliament for the week, pushing out Mr Hipkins’ first question time as Prime Minister.

As the weight of the mammoth storm’s impact became clear on Tuesday, leader of the house Grant Robertson said MPs would have other priorities.

“This an unprecedented storm which is affecting people and property across much of the North Island,” Mr Robertson said.

Instead of Mr Hipkins giving his Prime Minister’s statement and facing his first parliamentary grilling this week, that will now take place next week.

A house hit by a tree in Auckland. Photo: AAP

Mr Hipkins rode out the storm in Auckland. He was able to return to the capital in a New Zealand Defence Force plane later on Tuesday.

“I am hoping to get back to Wellington later on today, where I will get a briefing from the team at NEMA, who have now stood up the full national emergency response,” he said earlier.

On Monday, there was a behind-closed-doors spat between parties as to whether parliament would sit virtually this week.

Opposition party National was against the virtual sitting, before leader Chris Luxon changed his mind on the need for parliament given the cyclone’s carnage.

“It’s our view is that we need to be here doing our job,” he said.

“It’s obvious under a state of emergency that’s not going to be possible … events have superseded it.”

Maori Party co-leader Debbie Ngarewa-Packer hit out at National’s opposition to a virtual session as she drove to Wellington on Tuesday.

-with AAP