A powerful 6.5-magnitude earthquake rocked central New Zealand on Sunday, sending frightened people into the streets, halting trains and downing power lines.
However no tsunami alert was issued and no substantial damage was reported but the quake -- the strongest in a series of tremors in recent days -- smashed windows in the capital Wellington and sent blocks of masonry toppling from buildings.
One hotel was evacuated after structural damage was discovered, the airport was closed temporarily and suburban train services were stopped.
The quake hit at 5:09 pm (0509 GMT) 57 kilometres south-southwest of Wellington at a depth of 14 kilometres, the US Geological Survey said.
It was widely felt in the lower North Island and upper South Island and sent people rushing into the streets from cinemas and shops.
Electricity supplies were cut in many areas, trapping people in elevators.
Although no substantial damage was reported, New Zealand remains on edge about severe earthquakes following a devastating tremor two years ago that killed 185 people in the main South Island city of Christchurch.
"Biggest one I've ever felt here in Wellington. Scary stuff," one web user wrote on the Stuff news website.
"I must admit I used to get a bit sick and tired of all the attention Christchurch kept getting in the news, and kept thinking 'oh here we go again' but not anymore."
Although Wellington is on an earthquake fault line and prone to regular tremors, office worker Alice Midgley said this was "the first time I was afrightened."
The powerful quake was followed minutes later by another of 5.5 quake and came about 10 hours after a 5.8 tremor in the same region which has been rocked by multiple quakes in recent days.
Dozens of earthquakes were recorded today, with New Zealand's GeoNet earthquake monitoring service describing the 6.5 tremor as "severe".
Wellington Civil Defence controller, Bruce Pepperell, said there were reports of structural damage to a number of buildings in the city but there was only one report of injury.
"While some buildings are damaged and have been evacuated, the city and region has by no means ground to a halt," he said.
Seismologist Anna Kaiser told the New Zealand Herald that earthquakes of this magnitude were not unusual in the region.
"When we get one of these events there will be increased seismicity in the region and there's always the possibility of a larger event but it's unlikely."
The Pacific Tsunami Warning Centre said earthquakes of such magnitude can generate local tsunamis but there was no threat of a "destructive widespread tsunami".
New Zealand's civil defence authorities said it was "unlikely to have caused a tsunami that will pose a threat to New Zealand".
The recent quakes have been centred about 200 kilometres north of Christchurch which was devastated by a deadly 6.3-magnitude quake in February 2011.
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.