Wellington: At least 50 people were believed to be on or near a volcano on New Zealand's White Island when it erupted on Monday, "with a number" of them remain unaccounted for, police said.
The police were working with the National Emergency Management Agency to coordinate a search and rescue operation following the eruption.
According to The Guardian, Police Deputy Commissioner John Tims confirmed that one person had died.
The eruption occurred about 2:11 pm in New Zealand (around 6:45 am in India).
"Ashfall may impact areas distant from the volcano. People should stay out of designated restricted zones," the New Zealand Police said.
A no-fly zone has been established.
"While it was initially believed there were approximately 100 people on or near the island at the time of the eruption, we now believe there were fewer than 50," the police said in a statement.
"Some of those people have been transported to shore, however a number believed to be on the island are currently unaccounted for."
Families of those affected were gathering at Whakatane wharf where people covered in ash were also being treated.
"Of those transported to the wharf, at least one has been critically injured," the police added.
Earlier, the Prime Minister said about 100 people had been believed to on or near the island.
"All our thoughts are with those affected at this stage," she added.
Meanwhile, GeoNet, the country's geological hazard information centre, said that the "short-lived" eruption generated an ash plume of over 12,000ft metres above the vent, adding the ash fall appeared to be confined to the island.
"We have seen a steady decline in activity since the eruption," it added.
The agency put the Volcanic Alert Level to Level 3, with the Aviation Colour Code remained at Orange.
New Zealand Prime Minister Jacinda Ardern has said that search and rescue crews are assisting at the site of the eruption, located 48 kilometers from the eastern coast of North Island.
Ardern had said that an estimated 100 people were believed to be on the island, but the police later lowered the figure.
Deputy Prime Minister, Winston Peters tweeted on the incident and expressed "deep sympathy to all those grieving".
The White Island is New Zealand's most active cone volcano, according to the GeoNet. It has been built up by more than 150,000 years of volcanic activity. The island itself is visited by more than 10,000 people every year.
The incident was caught on video by people who had just left the island. Watch below the video taken by Michael Schade:
(With inputs from agencies)