At least six deaths were confirmed by the police, five people died at the time of the blast or soon after, while a sixth person died Tuesday night at an Auckland hospital.

Eight others are still missing after the volcano erupted suddenly on Monday, and 30 people are in seven hospitals, according to the police.

At least two Chinese nationals were among the 47 people who were on New Zealand's White Island at the time of a volcanic eruption on Monday, according to New Zealand's police and the Chinese Embassy in New Zealand on Tuesday.

Two Chinese nationals have been hospitalized, the embassy said in a statement, adding that officials from the Chinese embassy visited the hospital. The embassy officials met with the hospital staff and asked them to do their best to treat the injured and ensure their smooth recovery.

The Chinese embassy will continue to maintain communication and contact with relevant parties and provide consular protection and assistance for Chinese nationals.

The police have announced a criminal investigation into how an eruption at the White Island volcano led to the deaths. 

Two people from Britain, four from Germany, 24 from Australia, five from New Zealand, two from China, one from Malaysia, and nine from the United States were on the White Island at the time of the eruption, according to police. 

The eruption began at about 2:30 p.m. local time (0130 GMT) on the island, about 50 kilometers from the east coast of North Island, spewing smoke and debris into the air.

"It is very much an evolving situation, and of course, all our thoughts are with those affected," New Zealand Prime Minister Jacinda Ardern told the media shortly after the incident.

The White Island volcano is among New Zealand's most active volcanoes.