Police in New Zealand are planning a mission to volcanic White Island on Friday to retrieve bodies of people killed in this week’s eruption, while the known death toll from the disaster climbed to eight, with two people dying in hospital.

Eight more people are missing and presumed dead, buried under ash and debris from Monday’s eruption. More than 20 people are in hospital, many with severe burns, while seven others have been transferred to burns units in Australia.

“I can now confirm that we are finalising a plan to recover the bodies from Whakaari/ White Island Friday morning,” police Deputy Commissioner John Tims said in a statement on Thursday, adding families will be briefed on the operation.

Another police officer, Deputy Commissioner Mike Clement, later told a news conference the mission was risky and that a team would deploy at first light on Friday.

Six bodies could be seen and there would be “very limited”opportunity to search for the other two, he said.

“A lot has to go right for this to work,” Clement said.

The volcano on White Island was “highly volatile” and could erupt again within days, said authorities.

There are no signs of life on the uninhabited island.

“We are now living with a growing sense of desperation to bring home those that we know are there and those we love,” said Judy Turner, the mayor of Whakatane, the nearest town on the mainland. “The frustration of those families most affected is completely understandable. No news is not good news for people in this situation.”

The volcano, a popular tourist destination for day-trips, erupted on Monday, spewing ash and steam over the island.

There were 47 people on the island, also known by its Maoriname Whakaari, at the time of the eruption. Twenty-four of those were from Australia, nine from the United States, five from New Zealand, four from Germany, two each from China and Britain and one from Malaysia.

Graham Leonard, a senior scientist at New Zealand’s geological science agency GNS Science, said monitoring equipment still active on the island put the risk of a further eruption over the next 24 hours at 50% to 60%, up from 40% to 60% on Wednesday.

“Today is less safe than yesterday and the day before,” he said.

In the event of another eruption, anybody on the island could be “pummeled to death” by flying rocks or overcome by ash and gases in temperatures exceeding hundreds of degrees Celsius, said GNS Science volcanologist Nico Fournier.

Clement said earlier the risk of both another eruption and toxic gases were simply too great on Thursday to expose recovery teams, although the situation was being constantly reviewed.