6.4 quake jolts North and South Islands

An earthquake measuring 6.4 on the Richter scale shook the North Island and parts of the upper South Island early today.

The strong quake was centred off the coast of Taranaki in the Tasman Sea, 160km northwest of Wellington at a depth of 150km.

Geological and Nuclear Science duty seismologist Peter McGinty said the tremor hit at 4.08am.

Its proximity in the South Taranaki Bight meant the quake was felt in many parts of both islands -- from Wanganui and as far south as Christchurch.

"This was to do with the plate boundary," he told NZPA.

"At that depth it's just part of the normal process at the plate boundary."

The institute was not expecting any aftershocks and did not believe the tremor was a precursor to a massive earthquake. "We never know but it's unlikely."

New Plymouth and Wanganui police said by 6am no reports of damage had been received.

A spokesman for Wanganui police said the quake lasted more than 30 seconds but felt like a "gentle shake".

Nelson police said they had received no reports of damage and the quake had not been felt strongly.

However, Blenheim police said it had been "a strong jolt".

Emergency services said there had been a few reports of items falling off shelves.

It followed a minor tremor of 2.9, located 120km north of Dunedin yesterday at 8.19pm and was the biggest earthquake since November, when a tremor measuring 7.2 struck 240km off the Southland coast at a depth of 33km.

- NZPA