New Zealand civil defence authorities cancelled a tsunami warning on Thursday but warned of possible stronger than normal ocean currents around the east coast of the country after a magnitude 7.8 earthquake struck in the Pacific Ocean north east of the country.

It said a tsunami was generated by the earthquake around the Kermadec Islands, around 1180km north east of New Zealand, but scientists has advised it was of no threat to New Zealand.

"However, they expect that there will be unusually strong tidal surges and currents," the Civil Defence Ministry said in a statement.

The first surge had been expected at eastern coastal areas of the North Island just before 9 a.m. local time (2100 GMT), but there were no reports of unusual activity.

The quake struck at 07:03am Thursday local time at a depth of just one kilometre, the United States Geological Survey (USGS) said.

Its epicentre was 160km east of Raoul Island and 914 kilometres from the Tongan capital, Nuku'alofa.

A small research team on Raoul Island, the main island in the group was reported safe and well.

USGS revised the quake's magnitude slightly downward from an earlier reading of 7.8.


Source: Agencies