Australian Prime Minister Scott Morrison is fearing for those still unaccounted for following the White Island explosions yesterday.
Some of those visiting the island were able to be rescued by nearby boats shortly after the eruption.
Authorities today said 31 people were being treated at hospitals and three had been discharged. The injured are being treated in Wellington, Auckland, Tauranga, Waikato and Christchurch. Some are in critical conditions.
Mr Morrison, speaking to media this morning, said what should have been a joyous time for Australians on holiday in New Zealand turned to tragedy.
"Their visit turned to horror," he said.
Among those being treated at various hospitals throughout New Zealand, Mr Morrison said 13 were Australian nationals. There are another 11 Australians unaccounted for.
Of the five confirmed dead, it's believed three were Australian - however it is yet to be confirmed, Mr Morrison said.
"Yesterday there were 24 Australians enjoying a wonderful cruise in New Zealand, talking in those sights together, enjoying life, a peaceful time," he said.
"The news we feared would be very difficult and it is proving to be so."
The 24 Australians, aged 17 to 72, took the option of a tour to White Island - something which Mr Morrison said many Australians, including himself, have done.
"Today is a very difficult day for Australians, as well as indeed yesterday, and for our cousins across the Tasman in New Zealand," he said.