WELLINGTON (REUTERS) - New Zealand police said early on Tuesday (Dec 10) they did not expect to find any more survivors from a volcanic eruption that killed at least five people, injured up to 20 and left more than two dozen unaccounted for.
The volcano, off New Zealand's North Island, erupted suddenly on Monday at about 2.11pm, spewing a plume of ash thousands of feet into the air.
About 50 people, New Zealanders as well as foreign tourists, were feared to have been nearby at the time and several were seen near the rim of the crater minutes before the eruption.
Police said in their statement that there were no more signs of life on White Island after rescue helicopters and other aircraft conducted a number of aerial reconnaissance flights, though it was unclear how many people were unaccounted for.
The rescue services have been unable to reach White Island as it remains too dangerous.
"Police believe that anyone who could have been taken from the island alive was rescued at the time of the evacuation," the statement said.
"Police (are) working urgently to confirm the exact number of those who have died," it said, adding that a ship would approach the island at first light on Tuesday to deploy drones and observational equipment to further assess the situation.
Many day tours visit the island regularly, and one from the Ovation of the Seas cruise liner was there at the time.
Mr Michael Schade, an engineering manager from San Francisco, was one of the tourists who made it off the island just before the eruption.
In a video Mr Schade posted on Twitter as he sped away from the island by boat, a huge plume of white ash soars into the sky as a group of frightened tourists huddles close to the shore.
"This is so hard to believe," Mr Schade said. "Our whole tour group were literally standing at the edge of the main crater not 30 minutes before."
A crater rim camera owned and operated by New Zealand science agency GeoNet shows groups of people walking towards and away from the rim inside the crater, from which white vapour constantly billows, in the hour leading up to the eruption.
At 2pm, the crater rim camera catches a group of people - tiny specks in relation to the vast volcano - right at the edge of the rim.
At 2.10pm - just a minute before the eruption - the group is headed away from the rim, following a well-worn track across the crater.
A webcam monitoring the volcano shows at least one group of tourists was inside the crater moments before it erupted and blanketed the area in a massive ash cloud.
White Island is about 50km from the east coast of North Island and huge plumes were visible from the mainland.
Volcanologists said the ash plume shot 12,000 ft (3,658m) into the air.
"We know that there were a number of tourists on or around the island at the time, both New Zealanders and visitors from overseas," Prime Minister Jacinda Ardern told a news conference. "I know there will be a huge amount of concern and anxiety for those who had loved ones on or around the island at the time. I can assure them that police are doing everything they can."
On Twitter, Australian Prime Minister Scott Morrison said Australians had been affected by the eruption and the government was trying to learn more. Twenty-four Australians were on White Island when the volcano erupted, Australian media said.
New Zealand Cruise Association chief executive Kevin O'Sullivan said: "We believe there is a tour party from Ovation of the Seas involved in the White Island eruption. We have no further details at the moment."
Ovation of the Seas is a 16-deck cruise ship owned by Royal Caribbean Cruises. It can take nearly 5,000 passengers and has a crew of about 1,500.
It is docked at Tauranga, on the North Island, on a cruise that began in Sydney on Dec 3.
"We can confirm that a number of our guests were touring the island today," a company representative said in an e-mailed statement. "We do not have any additional details to share at this time."
There seemed to be no danger for people in coastal areas farther away, the authorities said.
The eruption was unexpected, but not unusual, an expert said.
"Sudden, unheralded eruptions from volcanoes such as White Island can be expected at any time," volcanologist Shane Cronin from the University of Auckland said in comments published by the Australia Science Media Centre.
"We know hydrothermal and so-called 'phreatic' eruptions can occur suddenly and with little or no warning because they are driven by the expansion of super-heated water into steam," he added.
Geological hazard tracker GeoNet raised the alert level for the White Island volcano in November owing to an increase in volcanic activity.
Just last week, GeoNet volcanologist Brad Scott said in a report that moderate volcanic unrest continued at White Island, with substantial gas, steam and mud bursts observed at the vent located at the back of the crater lake.
The White Island volcano is one of New Zealand's most active.
Twelve people were killed on the island in 1914 when it was being mined for sulphur. Part of a crater wall collapsed and a landslide destroyed the miners' village and the mine itself.
The remains of buildings from another mining enterprise in the 1920s are now a tourist attraction, according to GeoNet.
The island became a private scenic reserve in 1953, and daily tours allow more than 10,000 people to visit the volcano every year.
The island is also known by the indigenous Maori name Whakaari.