Passengers on board Australia's biggest cruise liner caught up in New Zealand's volcano tragedy describe the horror of watching the injured be brought back to the ship

• Whakaari, also known as White Island, erupted about 2pm local time on Monday 
• Five people died, 18 were rescued and at least 27 tourists are unaccounted for
• Tourists who were aboard Ovation of the Seas are believed to be among missing
• The cruise ship, which originated in Sydney, has docked in Tauranga overnight
• Passengers have said they were 'grateful' they didn't go on a tour of Whakaari 

Tourists on Australia's biggest cruise ship are 'grateful' they decided to stay on board after passengers and crew members were caught up in New Zealand's volcano tragedy.  

At least five people died in the powerful eruption on White Island, also known as Whakaari, at 2.11pm local time on Monday when an estimated 50 tourists were on or around the volcano crater.

Eighteen survivors were evacuated - some suffering severe burns - leaving an estimated 27 people unaccounted for. 

Australians were among the visitors on Whakaari from a nearby cruise ship, the Ovation of the Seas, which originated in Sydney.  

The vessel, which has 4579 passengers and 1595 crew on board, is docked in Tauranga, 90 kilometres from White Island. 

Kasey Bebrouth, who lives in Ipswich, Queensland, wrote on Facebook she was safe on the cruise ship after choosing not to tour the island.

'Okay so me and Marty are on the Ovation of the Seas and yes people have been hurt,' she wrote.

'The boat is staying overnight. At this point we are OK but very grateful that we stayed on the ship.

'We thank everyone for their kind words and worries. We will post more when we know more, just know that we are safe.' 

Her friend Stephen Irvine told News Corp he had been messaging the mother-of-one after the eruption and she said she saw injured passengers covered in ash being carried back to the boat.  

'The passengers have been offered counselling,' Mr Irvine said.

Stephanie Wright, whose Facebook says she's a lighting technician at Royal Caribbean International, also wrote a status about being safely docked at Tauranga.

'This is absolutely tragic. I'm on Ovation of the Seas,' Ms Wright wrote.

'We're docked overnight in Tauranga hoping and waiting for news and the return of our crew and passengers. 

'Keep them in your thoughts and if you pray, hold them there too.'  

The captain of the vessel announced one crew member and a group of passengers were on the island when the volcano erupted, New Zealand Herald reported.  

Passenger Nigel Walker, from Wollongong, south of Sydney, extended his thoughts to those missing.   

'It's tragic... I was only saying to my mother-in-law before the cruise that White Island would be a great place to visit,' he said. 

Royal Caribbean issued a statement saying the ship would stay in the nearby port overnight 'until we learn more about the situation'.

The vessel, which embarked on a 12-day cruise from Sydney, was supposed to sail to Wellington on Monday evening before touring New Zealand’s South Island and returning to Circular Quay.  

Michael Schade, a traveller from San Francisco, said his tour group was standing at the edge of the main crater less than 30 minutes before the blast. 

'My god, White Island volcano in New Zealand erupted today for first time since 2001,' he wrote 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.'

Mr Schade shared video footage of the destruction and some of the tourists who managed to escape onto his vessel.

'Praying for them and their recovery. Woman my mum tended to was in critical condition but seemed strong by the end.

'My thoughts with the families of those currently unaccounted for, the people recovering now, and especially the rescue workers.' 

Brazilian tourist Allessandro Kauffmann, who was on a tour to the island, shared a series of Instagram stories throughout the day and said he fled moments before the eruption.  

'Some people have extensive burns on their bodies. Two tours on the volcano. Ours was the first. The other one right after,' he said after escaping. 

'We left the island and wasn't even five minutes before it erupted. This other tour that arrived after couldn't leave in time.

'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.' 

His partner Aline Moura shared videos of the eruption to Instagram to recount her day.

'This was the end of today's trip that I had. The beginning was excellent, lots of cool pictures, amazing experience,' she wrote.

'But nature is autonomous and man has no control over his will. 

'Surely we never forget that day. Let us pray that everyone will be fine.' 

Speaking in a series of Instagram stories, the couple recalled how their boat helped rescue people who suffered burns from the eruption. 

Police and emergency services haven't been able to reach or make contact with those trapped by the blast.

National Operation Commander Deputy Commissioner John Tims told reporters on Monday evening that it's currently too dangerous to search for survivors.  

'There are possibilities of further eruptions. The physical environment is unsafe for us to return to the island,' he said.

'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.'