At least five people are dead with many others reported missing — and authorities now fearing the worst — after a volcano erupted Monday at a popular tourist site in New Zealand.

Several dozen visitors, including some from a Royal Caribbean cruise ship, were on or near White Island when it erupted at 2:11 p.m. local time, releasing thick clouds of ash about 12,000 feet into the air. Some 18 people suffered serious burn injuries and were rescued.

Police do not believe there are any survivors among the missing, following what scientists called a “throat-clearing kind of eruption.”

“No signs of life have been seen at any point,” New Zealand Police said in a statement. “Police believe that anyone who could have been taken from the island alive was rescued at the time of the evacuation. Based on the information we have, we do not believe there are any survivors on the island.”

Deputy Commissioner John Tims said at a news conference that he didn’t know how many are still unaccounted for, estimating that figure to be in the “double digits.”

Tims said search efforts were delayed for the night after experts deemed the island unstable. The New Zealand military is expected to examine the perimeter of the island at first light on Tuesday, with drones and other equipment.

“No signs of life have been seen at any point,” according to a statement the police issued shortly after midnight on Tuesday local time.

Prime Minister Jacinda Ardern told reporters at an earlier news conference that both New Zealanders and foreign visitors were on or around the island in the Bay of Plenty when the volcano erupted. White Island, which bills itself as “New Zealand’s most active volcano,” is uninhabited, but frequented by tourists.

“I know there will be a huge amount of concern and anxiety for those who have loved ones on or around the island at the time, and I can assure them police are doing everything they can,” said Ardern, who planned to travel to the island along with New Zealand’s Minister of Civil Defense, Peeni Henare.

When Lauren Urey called her parents Monday, the 32-year-old newlywed was excited. The Royal Caribbean cruise ship that Lauren and her husband, Matthew, were spending their honeymoon on had just docked in Tauranga, New Zealand, and the couple from Richmond had an action-packed day ahead of them.

“She said they were going to the volcano,” Lauren’s mother Barbara Barham told The Washington Post. “My husband was joking around and said, ‘I hope it’s not a live volcano.’ ”

Actually, Lauren responded, it is. The Ureys had plans to visit White Island, but Lauren and Matthew, 36, “weren’t concerned that there was any chance of an eruption,” Barham said.

The American couple were rushed to a hospital with severe burn injuries, Barham said, but their families have since heard no updates about their condition.

A number of visitors to the island during the eruption came from the Ureys’ cruise ship, the Ovation of the Seas, which offered an excursion to the volcano. In a statement, the New Zealand Cruise Association’s CEO Kevin O’Sullivan extended “heartfelt concern to the passengers and their families.”

Photos of the volcano’s crater rim minutes before the eruption showed people walking nearby, the New Zealand Herald reported.

One video taken of the eruption from a boat offshore captured thick clouds rising from the island. A voice could be heard frantically telling passengers to go inside the boat’s cabin. In another clip, the island appeared to be completely enveloped by ash.

New Zealand’s National Emergency Management Agency warned on Twitter on Monday that it was “hazardous in the immediate vicinity of the volcano” and urged people to pay attention to detailed safety advice, adding: “Act on it promptly.”

The same dangerous conditions prevented police and rescue services from reaching the island, Tims said, with experts warning that more eruptions could be possible.

Barham told The Post she and her husband, who live southeast of Richmond, had no idea that chaos was unfolding halfway around the world — and that their daughter was involved. Then, Barham said she got a call from Royal Caribbean shortly after midnight Monday Eastern time asking her if she had heard from Lauren. The newlyweds hadn’t returned to their cruise ship after the volcano tour and were missing.

Soon, Barham’s phone was ringing again. It was Matthew’s mother, and she had just received a distressing voice mail from him.

“Her son called and said that they had been on the excursion and there had been a volcano eruption and they were burned very bad,” Barham said. “He said he would try to call as soon as he could, but talking and making phone calls was difficult. His hands were so badly burned it was hard for him to make a phone call.”

In the voice mail, Matthew said he and Lauren, who also suffered similar injuries, had been taken to a hospital. Their families haven’t heard from them since, Barham said.

“Obviously, I’m panicking,” she said. “I don’t know how to act. I feel like I should be crying, but I can’t even cry.”

But as Barham tuned into news coverage about the eruption, the shock began to give way to anger. Experts had reported increased volcanic activity on the island weeks before Monday’s incident.

“I’m just livid,” she said. “There’s been warnings about it. … My son-in-law never would have booked the excursion if he knew there was any chance of them being injured.”

GeoNet, an agency that provides geological hazard information for New Zealand, issued multiple reports of “volcanic unrest” on the island, going as far back as late October.

“Moderate volcanic unrest continues at Whakaari/White Island, with substantial gas, steam and mud bursts observed at the vent located at the back of the crater lake,” stated a report from last Tuesday.

During the news conference, Ardern declined to answer a question about whether visitors should have been allowed to go to the island.

“In this moment in time, the absolute focus needs to be the search and rescue operation,” she said. “There will be a time and a place to undertake further assessments. Now, we have to focus on allowing the police to do their job and focus on those who were in the vicinity of the island at the time.”

Emanuel Stoakes in Christchurch, New Zealand, contributed to this report.