A 6.9-magnitude earthquake has struck New Zealand, rattling the capital Wellington and some other cities.

The quake on Sunday hit 57km southwest of Wellington at a depth of 10.1km, the US Geological Survey said.

There were no immediate reports of major damage and injuries after the earthquake but some water mains were broken, windows smashed and power lines downed. 

Wellington police inspector Marty Parker said there had been minor structural damage that had left parts of the city without power.

No tsunami alert was issued.

New Zealand's GeoNet earthquake monitoring service described the 6.9 tremor which was felt widely as "severe".

"There was a rocking and rattling which lasted about 30 seconds," a resident in the resort town of Nelson told the AFP news agency.

It tremor was followed minutes later by another quake with a magnitude of 5.5 and came about 10 hours after a 5.8 tremor in the same region, which has been hit by multiple quakes in recent days.

Recent quakes have been centred about 200km north of New Zealand's second largest city Christchurch, where a 6.3-magnitude quake in February 2011 toppled buildings onto lunchtime crowds, leaving 185 people dead.

The country sits on the so-called "Ring of Fire", the boundary of the Australian and Pacific tectonic plates, and experiences up to 15,000 tremors a year.

Source: Agencies