Active volcano's alert level raised

White Island. File photo / Alan Gibson

An active volcano in the Bay of Plenty is showing signs of increased activity.

The aviation alert level for White Island off the coast Whakatane has been lifted by GNS from green to yellow.

Its crater lake had recently started to re-fill and gases were now "vigorously streaming through it", GNS said.

"Airborne gas measurements made yesterday show that the discharge of some sulphur gases has increased. During the past few weeks there has also been some minor volcanic tremor" duty volcanologist Michael Rosenberg said.