Unusual tidal movement is reported in parts of Poverty Bay in New Zealand.

The level of water has been falling in Gisborne harbour and the tide has been receding at Waikanae Beach.

The Emergency Management Office there confirms the water has been receding and then returning.

Controller Jon Davies told Morning Report there had been a sudden drop of up to 1 metre in places.

A tsunami surge of water measuring one meter has reached Northland.

Civil Defense Minister John Carter said the surge reached Tutu-kaka Harbour, north of Whangarei and Waitangi.

Northland Civil Defence group controller Mike Manley said there were no reports of damage so far.

He said officials are concerned at reports that people have been ignoring warnings to stay away from beaches.

A 40cm surge has reached Gisborne, while Pitt Island in the Chathams has been hit by a 1.5 metre surge and consistent one metre surges.

In Tonga, public radio warned people to seek higher ground, with crowds gathering in elevated areas.

A 50 centimetre tsunami wave has been reported by the Met Office in Samoa.