Dec. 10 (UPI) -- At least six people were confirmed dead Tuesday as New Zealand police launched a criminal investigation into deaths caused by a volcanic eruption on White Island.
During a news conference, New Zealand Deputy Commissioner John Tims said the conditions and scope of the investigation would be announced later.
He confirmed that 47 people were on or near the island Monday when the volcano erupted at 2:11 p.m.
Eight people were missing and presumed dead, he said.
"We absolutely believe that everyone that could have been taken from the island yesterday were rescued at the time of the evacuation," he said. "A number of flights were carried out throughout the day and no signs of life were seen."
At least 30 people were being treated for injuries at hospitals throughout the country, including 25 in critical condition. Another five were in serious, but stable condition.
Of those involved, police confirmed that 37 had been passengers and one had been a crew member of the Royal Caribbean International's Ovation of the Seas cruise ship.
The nationalities of those who were near the volcano when it erupted consisted of 24 Australians, nine Americans, five New Zealanders, four Germans, two Chinese, two Britons and one Malaysian, Tims said, adding that until the identification process is completed, "I cannot break down those numbers any further."
U.S. Ambassador to New Zealand Scott Brown in a statement confirmed that Americans are among "those injured and missing" but could not provide more specific information "out of consideration for those involved, as well as privacy concerns."
Pete Watson, Ministry of Health spokesman, said of those injured, 27 suffered from greater than 30 percent total body surface burns and many of them have inhalation burns that require airway support. The injured range in age from 13 to 72, he said.
"It's possible not all of the patients will survive," he said.
All burn wards were at capacity, he said, and some patients may be transferred to Australia.
The police were working to access the island and were in the process of determining its conditions, Tims said, adding, "We are doing everything we can to get back to the island."
However, volcanic tremors on the island "significantly increased" making search and rescue operations more difficult.
"This has been accompanied by vigorous steaming and localized mud jetting in several of the craters created by the eruption on Monday. We interpret these signals as evidence of continued high gas pressures within the volcano," GeoNet volcanologist Craig Miller said.
Known locally as Whakaari Island, the privately owned White Island is home to the most active cone volcano in the nation and is visited by more than 10,000 people per year, according to GeoNet.