A person takes photos of volcanic eruption at New Zealand's White Island, Dec. 9, 2019. (Photo provided by Michael Schade/Handout via Xinhua)

New Zealand police launched an investigation on Tuesday after a volcanic eruption on an island popular with tourists killed five people, injured more than 30 and left eight people missing, who are presumed dead.

Prime Minister Jacinda Ardern said reconnaissance flights showed no signs of life on White Island, as eyewitnesses detailed the horrific burns suffered by those caught up in Monday's eruption.

"To those who have lost or are missing family and friends, we share in your grief and sorrow and we are devastated," Ardern said.

Police said 47 people were on the uninhabited island at the time of the eruption - 24 from Australia, nine from the United States, five from New Zealand, four from Germany, two each from China and the UK and one from Malaysia.

Police said an investigation into the deaths on White Island had been launched but it was not a criminal investigation.

New Zealand's geological hazards agency GeoNet raised the alert level for the volcano in November because of an increase in volcanic activity. Yet, daily tours bring more than 10,000 visitors to the privately owned island every year.

"I have to say that I'm very surprised to hear there were visitors there today, because scientists seem to have been well aware that White Island was entering a phase of heightened activity," said Drexel University volcanologist Loÿc Vanderkluysen.