(Photo taken on Dec. 13 shows a recovery operation at White Island/Whakaari, New Zealand undertaken by New Zealand defense personnel and police.)[Courtesy of New Zealand Defence Force]

SYDNEY - New Zealand police confirmed Saturday that another person has died of injuries sustained in this week's eruption of a volcano off the country's North Island, bringing the official death toll to 15.

A police dive team continues to search waters surrounding the volcano for two more people who remain missing, presumed dead, on White Island, which erupted on Monday afternoon with 47 people -- mostly tourists -- in the vicinity.

In a statement on Saturday, the police said the search is hampered by poor visibility and contamination of the water with toxic volcanic gasses, with divers reporting a number of dead fish and eels washed ashore and floating in the water. Divers have to be decontaminated with fresh water each time they surface.

On Friday a specialist team of police and defense personnel recovered six bodies which could not be retrieved in the immediate aftermath of the eruption in a high-risk operation, in the face of a 50-60 percent chance of further eruptions on the island.

Several other victims are still being treated in hospitals across New Zealand, mostly for burns. The number of critically injured patients has seen New Zealand burns units stretched to capacity.

Australians comprised over half of those caught up in the eruption, with nationals from the United States, New Zealand, Germany, China, Britain and Malaysia also affected.

Several injured Australians have been transported back to Australia for treatment in local hospitals.

Meanwhile, the police confirmed on Friday that the formal disaster victim identification process has begun, with the first person to have formally been identified as Krystal Eve Browitt, 21, of Melbourne, Australia.

The police stressed the identification process is stringent and could take some time as it would be "unforgivable" to get the process wrong.

White Island, roughly 50 kilometers off the coast of New Zealand's North Island, is the country's most active cone volcano and a popular tourist destination, with over 10,000 people visiting each year through daily tours of the site operated by a private company.