Multiple mid-sized earthquakes were recorded near White Island in the Bay of Plenty overnight.
The largest of the five quakes was a magnitude 4.1, which occurred around 10km east of the island around 11.30pm.
White Island is an active volcano situated around 50km from the Bay of Plenty coast.
GeoNet has the Island on a level 1 alert, with a minor risk of volcanic unrest.
GeoNet reported four other shakes within two hours of this, ranging from magnitude 2.5 to magnitude 3.4.
The events were all about 16km in depth.
GeoNet scientist Jonathan Hanson said there were two main shakes estimated by GeoNet as being "moderate" and those were followed by a few aftershocks.
"There's a lot of activity up in the Bay of Plenty and these I guess are slightly higher than the daily norm, but they're not uncommon at all I would say," he said.
"At the moment we don't think there's any link to the volcano, but we're keeping an eye on that."