One killed after New Zealand volcano erupts on island

One person is dead and as many as 27 people are unaccounted for after New Zealand's White Island volcano erupted on Monday.

More fatalities are likely, police said.

Deputy Commissioner John Tims said 23 people had been taken from White Island in the country's Bay of Plenty, some of whom are injured.

He was unclear about the number who remained and were unaccounted for but said the total number of people on the island when it erupted was fewer than 50.

The island, a favourite of tourists, erupted with a large plume of ash and steam Monday.

New Zealanders and foreign tourists are believed to be involved, police added.

Mr Tims said it was too dangerous for police and rescue services to travel to the island but they wanted to urgently get back as quickly as they could.

He said there had been no contact with those who remained missing on the island.

"There remain a number of people on the island who are unaccounted for," a statement from police said.

"My god," wrote Michael Schade on Twitter as he posted video of the eruption.

"My family and I had gotten off it 20 minutes before, were waiting at our boat about to leave when we saw it. Boat ride home tending to people our boat rescued was indescribable."

His video showed a wall of ash and steam around the island and helicopters badly damaged and covered in ash.

New Zealand Prime Minister Jacinda Ardern said people who were injured in the eruption were being transported to shore.

She said the incident appeared to be "very significant".

"All our thoughts are with those affected," she said.