Warnings are being issued for New Zealand coastlines, including Mount Maunganui, following a 7.7 earthquake southeast of Loyalty Islands.

The National Emergency Management Agency have advised that New Zealand coastal areas may experience strong and unusual currents and unpredictable surges following the quake.

Areas under threat include Ahipara to Bay of Islands, Great Barrier Island, and from Matata to Tolaga Bay, and NEMA advise that people in these areas should stay off the beaches and shore areas.

"Strong currents and surges can injure and drown people. There is a danger to swimmers, surfers, people fishing, small boats and anyone in or near the water close to shore," says a NEMA spokesperson.

"People in or near the sea in the following areas should move out of the water, off beaches and shore areas and away from harbours, rivers and estuaries."

Green marked area = 0.3 -1 metre maximum expected amplitude at shore.

The earthquake occurred southeast of Loyalty Islands at 2.20am.

There is no need to evacuate other areas unless directly advised by local civil defence authorities. Coastal inundation - flooding of land areas near the shore - is not expected as a result of this event.

NEMA is advising people to:

• Move out of the water, off beaches and shore areas and away from harbours, rivers and estuaries.
• Do not go to the coast to watch the unusual wave activity as there may be dangerous and unpredictable surges.
• Listen to local civil defence authorities and follow any instructions.
• Share this information with family, neighbours and friends.

The first tsunami activity causing these strong currents and surges may reach New Zealand in the areas around North Cape at approximately 04.20am New Zealand Daylight Time. This may be later and the first tsunami activity may not be the most significant.

Strong and unusual currents and unpredictable surges will continue for several hours and the threat must be regarded as real until this Advisory is cancelled.

This National Advisory has been issued following an assessment of information available. The situation may change as new information becomes available. Listen to the radio or TV for updates, or check www.civildefence.govt.nz

Estimates of expected earliest wave arrival times:

Note: These times are provisional and based on the best information available. Arrival times may be as much as one hour later and may be adjusted in subsequent messages.