Ash venting on White Island has seen alert levels raised once again.
The minor ash venting, which occurred on Saturday between 11.30-1.30pm, is the latest in a string of recent seismic activity.
The volcanic alert level was changed from level 1 to level 2. The alert level ranges from 0 to 5.
The aviation colour code has changed from yellow to orange. Aviation colour codes of green, yellow, orange and red are used as a quick reference for planes flying in the area.
Arthur Jolly, GNS Science Duty Volcanologist, said GNS staff had had on-island time restrictions imposed in light of the event.
He said continuing activity increased the likelihood of a bigger eruption.
"We had some eruptive activity in August and unrest indicators going back to July. It tapered off somewhat and then in November a small magma dome grew out in the former crater lake.
"Low level seismic activity has been continuing since July. A very big eruption, or one like Tongariro, that's a lot less likely but it can occur.
"We would urge caution for people visiting the area. It is an active volcano after all."