Wellington, Dec 9 (TIWN) At least five people were killed after the White Island or the Whakaari volcano in New Zealand erupted on Monday, police said, adding that the toll was likely to increase as a number of people were still unaccounted for.

Tourists were seen walking inside the crater of White Island volcano just moments before the eruption.

Police said 23 people had been rescued, but warned conditions were hampering the operation. The New Zealand military is now helping police.

White Island, also known as Whakaari, is one of the country's most active volcanoes.

Despite that, the privately-owned island is a tourist destination with frequent day tours and scenic flights available.

In a police briefing, Deputy Police Commissioner John Tims said due to the risks, emergency services were not able to access the island.

Therefore how many people remain there is unclear, but he added that "both New Zealand and overseas tourists" were believed to be involved. Police had previously said fewer than 50 people were on the island.