'Hugely concerning': PM says NZ ready to help Tonga

New Zealand Prime Minister Jacinda Ardern says that images of the volcanic eruption in Tonga are "hugely concerning" and agencies are trying to establish full communications with the Pacific island kingdom.

A tsunami hit Tonga when underwater volcano Hunga-Tonga-Hunga-Ha'apai erupted for eight minutes, throwing clouds of ash into the sky about 6pm on Saturday (NZ time).

Communications in all of Tonga have been cut off as a result of Saturday's eruption, making any assessment difficult, Ardern said, but the Defence Force and Foreign Ministry were working to establish what's needed and how New Zealand can help.

There are no official reports of injuries or deaths in Tonga, but communication with the island is very limited and local mobile phones were not working, Ardern told media this afternoon. 

The undersea cable has been affected, probably because of power cuts, and authorities are trying urgently to restore communications. Authorities are still trying to make communication with some of the smaller islands, she said.

Ash has stopped falling in Nuka'lofa, she said. A significant clean-up will be needed and a priority is the supply of water for Tonga.

The Tongan government has accepted a New Zealand Government offer for a reconnaissance flight, and an Orion will take off tomorrow morning, provided conditions allow. At present, ash has been spotted at 63,000 feet.

The Government also announced a $500,000 donation which was very much a starting point, and more funds would be provided ass required.

A naval vessel has also been put on standby to assist, if necessary.

Ardern said she had been in touch with Australia's Prime Minister Scott Morrison so that both governments can work in tandem in their response.

Ardern said she has not been able to speak to the Tongan Prime Minister because communications are so difficult.

"At the moment we are mainly receiving information from our High Commission ...unfortunately from the outer islands we don't have a lot of information," she said.

If necessary New Zealand would help with any repairs that may be needed on the undersea cable that carries communications.

Pacific Affairs Minister Aupito William Sio said the Tongan Consul General Lenisiloti Sitafooti Aho has confirmed that Tonga's Royal family are safe.

Tsunami alert for NZ areas

The west coast of the South Island is the latest part of New Zealand to be included in a warning about dangerous sea conditions following the eruption.

This morning, New Zealand's National Emergency Management Agency said coastal areas on the north and east coast of the North Island are expected to experience strong and unusual currents and unpredictable surges at the shore.

It then added west coast of the South Island and the Chatham Islands to the advisory area.

Conditions were dangerous for swimmers, surfers, people fishing, small boats and anyone in or near the water close to the shore  

A tsunami hit Tonga when underwater volcano Hunga-Tonga-Hunga-Ha'apai erupted for eight minutes, throwing clouds of ash into the sky, yesterday afternoon.

The eruptions were heard as booms or 'thumps' across the Pacific, in Fiji, Niue, Vanuatu and in New Zealand.

RNZ listeners from Northland, to Wānaka in Central Otago have reported hearing what sounded like gunshots, loud bangs, or sonic booms.

Waves flooded the capital Nuku'alofa yesterday, where video footage has shown water engulfing buildings.

Tsunami wave activity is being reported through the wider Pacific region, including as far north as Russia and Alaska and Japan, as well as Hawaii, east to Rapanui and the coasts of Panama and Chile.

The Ministry of Foreign Affairs and Trade said all New Zealanders in Tonga are advised to register their details on safetravel.govt.nz.

On Sunday it said there were no official reports of deaths or injuries in Tonga. New Zealand's High Commission in Nuku'alofa is in contact with local authorities and said damage assessments were underway.

An NZDF P3 Orion is on standby to fly over the area once atmospheric conditions allow.

There are currently 30 New Zealanders registered as being in Tonga.

Boats were damaged at Tūtūkākā Marina in Far North overnight after strong tidal surges. Photo:...
Boats were damaged at Tūtūkākā Marina in Far North overnight after strong tidal surges. Photo: Supplied via RNZ

Boats damaged in Far North

Large waves in New Zealand's Far North forced 120 people to be evacuated from late on Saturday as big swells from Cyclone Cody and the surge from Tonga's volcanic eruption begin to affect the country.

Cody was expected to bring gale force winds and large swells to the eastern coast of the North Island over the next few days.

Police said they received a number of reports regarding tidal surges from people based in the Far North between 11pm and 12am, including Te Rere Bay and Shipwreck Bay.

Police, Fire and Coastguard also assisted with evacuations of boats moored at Tuakaka Marina last night.

A number of boats and moorings were damaged by large waves washing ashore.

A camp site at Mahinepua Bay was also inundated, about 50 people were in the camp at the time and all were accounted for.

A Tutukaka resident told The New Zealand Herald that his boat and many others had been completely destroyed - and he was concerned there had been no civil defence alert beyond the general warning put out earlier.

"Multiple boats have been destroyed. The wave cleared the breakwater which is around 2.0m higher than the high tide line. There was absolutely no civil defence warning, no tsunami siren activated and no phone notifications."

He had seen a notice in the news earlier but took little notice, he said.

"We have had multiple tsunami alerts which has triggered the alarm system and boats have been completely fine."

He was concerned for the safety of those who lived on their boats in the marina.

A number of people on social media are also reporting they did not get a civil defence alert to their phones prior to the surge.

- RNZ and NZ Herald