A magnitude-6.4 earthquake has struck off the coast in the Bay of Plenty.

It hit 90 km north of White Island, 230 km east of Auckland at 5.14pm at a depth of 280 km.

Daniel McMahon from White Island Tours said operations would continue tomorrow as per usual.

He said the company was warned about earthquakes from time to time but today's tremor was nothing for anyone to worry about.

Click here to view Geonet's seismograph drum.

- NZ Herald staff