Scientists are warning there are heightened signs of volcanic activity at Mt Ruapehu and an eruption could be just weeks away.
GNS Science experts say pressure is building up in the crater lake at the volcano and there is now a high risk of an eruption.
Volcanologist Steven Sherburn said: “We think that the temperature a few hundred metres beneath crater lake is about 800C, but the lake itself is only about 20C.
“This suggests the vent is partly blocked, which may be leading to a pressure build-up beneath crater lake. A sudden release of the pressure may lead to an eruption.”