A New Zealand Navy helicopter takes off from Whakatane Airport as the mission to return victims of the White Island eruption begins. [Source: AP/AAP]

Six bodies have been airlifted off the White Island volcano in New Zealand out of eight believed to have been left there after Monday’s volcanic eruption.

The bodies have been flown to the naval vessel HMNZS Wellington.

The “high-speed” operation to recover the bodies was launched despite the risk of another eruption.

Dozens of tourists were visiting White Island when the eruption occurred – killing eight other people – 20 remain in intensive care with severe burns.

Conditions on the island were favourable, Deputy Police Commissioner John Tims said.

Relatives waited anxiously for the mission’s return after earlier attending a blessing near the island.

Some 47 visitors from around the world were on the island when it erupted. Twenty-four were from Australia, nine from the US, five from New Zealand, four from Germany, two from China, two from the UK, and one from Malaysia.

GeoNet, New Zealand’s geological hazard information site, said on Thursday there was a 50-60% chance of another eruption within the next 24 hours.

But families of the victims have been growing increasingly desperate for the bodies to be recovered.