'9 officially listed as missing after volcano eruption'

Steam rises from the White Island volcano. (Reuters file photo)

Nine people have been officially listed as missing after the eruption of a volcano on New Zealand's White Island, police said on Wednesday, seven of them Australians and two New Zealanders.

"This is not a complete list of the missing as we have been unable to speak with all next of kin involved," the police added in their statement.

The death toll from Monday's eruption stands at six and 30 injured.