Emergency crews scrambled to a popular tourist island off the coast of New Zealand on Monday afternoon, local time, as a volcano erupted and left at least one person dead and even more injured or missing.
The eruption occurred on White Island, also known as Whakaari, which sits about 30 miles (48 km) offshore from mainland New Zealand.
"At this stage, it does appear to be a very significant issue," Prime Minister Jacinda Ardern said of the incident.
Shortly after the eruption, authorities said as many as 100 tourists were on or near the island when it rumbled to life, but those estimates have since dropped to fewer than 50, according to Radio New Zealand. Twenty-three people, many of them with burn injuries, have been transported from the island via helicopter or boat.
Smoke bellows from Whakaari, also known as White Island, volcano as it erupts in New Zealand, December 9, 2019, in this image obtained via social media. GNS Science via REUTERS
"A number of injured people have been transported to Whakatane Hospital and Middlemore Hospital," the New Zealand Police said in a statement.
The police confirmed at least one fatality and said "it is likely there are others."
"There remain a number of people on the island who are unaccounted for," the police said. "Both New Zealanders and overseas tourists are believed to be involved."
The island has been deemed too dangerous for search and rescue efforts to continue at this time.
Jonathon Fishman, a spokesman for Royal Caribbean Cruises, told NBC News that several guests from the "Ovation of the Seas" cruise ship were among the tourists on the island at the time of the eruption.
"Please keep all those affected in your prayers," Fishman told NBC News.
Satellite images captured the huge plume of smoke and ash that spewed into the sky during the eruption.
White Island eruption was also visible on satellite images. ^AJ pic.twitter.com/Cx4LYHr9Ie
- MetService (@MetService) December 9, 2019
The New Zealand Civil Defense encouraged people living in or near the affected ash fall areas to consider staying indoors, closing windows and doors to limit the entry of volcanic ash and wearing a handkerchief or dust mask over the nose and mouth.
"Wear eyeglasses, NOT contact lenses as fine ash will get under the lens," they said in a post on Facebook.
GeoNet, the government earthquake agency, said in a statement that the eruption was "short-lived" and generated an ash plume 12,000 feet into the sky.
The agency issued a Volcanic Alert Level of three for the eruption, indicating a minor volcanic eruption with a majority of the eruption hazards located near the vent. The Volcanic Alert Level is a scale ranging from zero to five with five representing a major eruption.
An aerial view shows smoke bellowing above the crater of Whakaari, also known as White Island, volcano as it erupts in New Zealand, December 9, 2019, in this image obtained via social media. GNS Science via REUTERS
"Ash fall appears to be confined to the island and we do not expect more than a minor amount of ash to reach East Cape in the coming hours," GeoNet said. "We are aware that people were on the island immediately before the eruption and we express our concern for their safety."
White Island is known to be New Zealand's most active cone volcano, according to the agency.
Prior to the eruption, scientists had noticed a recent uptick in volcanic activity on the island, according to The Associated Press (AP).
On Nov. 18, GeoNet raised the Volcanic Alert Level on White Island from one to two following an uptick in sulfur dioxide gas, according to the AP. The agency also reported an increase in the strength of volcanic tremors in the weeks prior.