Five people are dead, dozens more are injured or still missing after a volcano erupted near a group of tourists off the coast of New Zealand – as authorities say it’s too dangerous to search for survivors.

Whakaari also known as White Island, located 48km (29mi) off New Zealand’s North Island, erupted around 2.11pm local time on Monday blowing huge plumes of smoke and debris 3,657m (12,000ft) into the sky.

A group of tourists had been deep inside the crater just moments before the blast while others on a boat to the island were forced to seek cover as thick, black smoked billowed towards them.

It is believed fewer than 50 people were on the island at the time of eruption and 23 have been evacuated and brought to the mainland on stretchers covered in ash.

National Operation Commander Deputy Commissioner John Tims confirmed five people are dead and multiple have been taken to hospital with burns, with the death toll expected to rise.

‘I can confirm there are five people now deceased from the eruption on White Island,’ Mr Tims told reporters on Monday evening.

‘A number of other people have been taken to a hospital. The number of people have burns as a result of the eruption. It is still too early for police to confirm how many people are involved.’

‘There are possibilities of further eruptions. The physical environment is unsafe for us to return to the island. It is important that we consider the health and safety of those that are going to rescue those on the island. So we will be taking that advice,’

The majority of tourists involved are believed to have come from the Ovation of the Seas cruise ship which departed Sydney last Wednesday with 4,579 passengers and 1,595 crew for 12-day trip.

Authorities are yet to confirm the nationalities of the people involved as they are unable to assess the island due to the current risk.

According to 9News, 24 Australians are believed to have been on the island at the time.

Sightseeing helicopters and one boat remain unaccounted for as a major rescue operation gets underway.

‘We know that there were a number of tourists on or around the island today, both from New Zealand and overseas,’ New Zealand Prime Minister Jacinda Ardern said on Monday.

‘I know there will be a huge amount of anxiety for those who have loved ones on or around the island at the time. I can assure them police are doing everything they can,’ Ardern said.

Ardern and Civil Defence Minister Peeni Henare will travel to the nearby Whakatane on Monday night.

Royal Caribbean, owner of Ovation of the Seas, issued a statement saying the ship would stay in the nearby port of Tauranga overnight ‘until we learn more about the situation’.

White Island is New Zealand’s most active volcano and had seen its last major eruption in 2001, with smaller events over the years until now.

Officials said it’s unlikely the volcano will erupt again in the next 24 hours but have warned people to stay away from the area.

‘It was not a particularly big eruption, it was almost like a throat clearing eruption and that’s why material probably won’t make it to mainland New Zealand,’ Dr Ken Gledhill said.

‘We can’t be certain it won’t erupt again in the next 24 hours,’ he said.

The island is frequently visited by tourists as part of organised boat tours from nearby Whakatane.

Geological hazard trackers GeoNet had registered moderate volcanic unrest on the island for weeks.

But the nature of volcano activity is unpredictable, with the eruption unforeseen by authorities.

A camera of the crater’s rim, run by monitoring agency GeoNet, set to take pictures every 10 minutes showed a string of people visiting the crater at 2.10pm.

The next shot taken, at 2.20pm, was unreadable as the blast had rendered the camera inoperable.

St John has dispatched seven helicopters to the island, but they are unable to land.

‘We are taking expert advice with regard to conditions to determine when we can safely access the island,’ a police statement read.

‘We can confirm there has been one fatality, and based on the information we have it is likely there are others.’

Police did not advise of any further information of the deceased person.

‘Of those transported to shore, at least one has been critically injured,’ a spokesman said.

‘Emergency services are working to ensure the safety of everyone involved, including rescue staff.’

Most people who have been rescued from the island suffered various stages of burns.

Tourist Michael Schade said he and his family were on the volcano just 20 minutes before it erupted and witnessed the blast as they were leaving the island.

‘This is so hard to believe. Our whole tour group were literally standing at the edge of the main crater not 30 minutes before. My thoughts with the families of those currently unaccounted for, the people recovering now, and especially the rescue workers,’ he said on Twitter.

‘My family and I had gotten off it 20 minutes before, were waiting at our boat about to leave when we saw it. Boat ride home tending to people our boat rescued was indescribable.

‘Praying for them and their recovery. Woman my mom tended to was in critical condition but seemed strong by the end. The helicopters on the island looked destroyed.

Allessandro Kauffmann, a Brazilian tourist who was in the first tour group for the morning said his group left the island ‘just in time’.

‘Some people have extensive burns on their bodies. Two tours on the volcano. Ours was the first. The other one right after. We left the island and wasn’t even five minutes before it erupted. This other tour that arrived after couldn’t leave in time,’ he said in an Instagram post.

‘Some people have serious burns. We had to stay to help those people who were on the island. The boat from this other tour was covered in ash from the volcano. Very tense talking about this. We just have to hope that all is as well as can be.’

Tourists from cruise liner Ovation of the Seas were visiting the island on Monday morning, according to the company’s chief executive Mark Cairns

Tourists have been travelling to White Island for years despite warnings from scientists that it could erupt at any time.

Between 2011 and 2016 the volcano to the north of New Zealand’s north island – which erupted injuring 20 on Monday – had a period of increased activity but still boatloads of tourists arrived.

Volcanologists at the time refused to step foot on the island because it was too dangerous and warned tourists not to go – but still the boats kept landing.