GNS Science has raised the alert level for White Island after the volcano erupted.
The agency says a moderate explosion eruption, lasting about a minute, happened just after 8pm Friday night.
GNS says the volcanic alert level has been raised from 1 to 2, which indicates minor activity.
White Island. Photo: GEO NET
The aviation colour code has been upgraded to orange, the second-highest alert level.
GNS volcanologist Arthur Jolly says the eruption was about the same size as the previous one in August 2012.
Dr Jolly says cameras on the island captured footage of the eruption, which flung hot mud up to 800 metres from the volcanic cone.
He says bad weather on Saturday prevented GNS from flying over the island to observe the volcano.