WELLINGTON - One person was dead in a volcanic eruption in New Zealand's White Island in the Eastern Bay of Plenty of the North Island on Monday about 2:11 pm local time (0111 GMT), with more casualties likely, according to the police.

The rescue operation is too dangerous to carry out now, the police said.

Previously, police said one person was left in critical condition.

"We are aware that people were on the island immediately before the eruption and we express our concern for their safety," GeoNet, the country's geological hazard information center, said on its website.

Media reports quoted New Zealand Prime Minister Jacinda Ardern as saying that around 100 people, including foreigners, were on or around the island at the time of the eruption, and some of those are "unaccounted for."

"A number of people are reportedly injured and are being transported to shore," she was quoted as saying.

According to videos released by local media, a group of people were desperate to get off the island when volcano erupted.

At least a group of passengers from the Ovation of the Seas cruise ship were on the island at the time of the eruption, according to a statement of the New Zealand Cruise Association, which is also waiting for further information.

Labor Party MP Tamati Coffey, who was outside White Island Tours in Whakatane, a town in the eastern Bay of Plenty Region, was quoted by local media as saying that people at the scene was "emotional" and "in tears" with "lots of hugging and crying."

The "short-lived" eruption generated an ash plume of over 3,000 meters above the vent, said GeoNet, 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 Color Code remained at Orange.