A powerful 7.8 magnitude earthquake pummelled central New Zealand early on Monday, killing at least two people, damaging roads and buildings and setting off hundreds of strong aftershocks.
Emergency response teams were already flying by helicopter to the region at the epicenter of the original 7.8 magnitude quake, which struck just after midnight some 91 kilometers (57 miles) northeast of Christchurch in the South Island, amid reports of injuries and collapsed buildings.
New Zealand's capital Wellington was a virtual ghost town with workers ordered to stay away while the local council assessed the risk to buildings. Severe weather with 140 kilometers per hour gale-force winds was forecast for the area, which could cause more damage, such as from glass loosened by the tremors.
The new tremor, a 6.2 quake recorded at about 1.45 p.m. local time (0045 GMT), was the most powerful of hundreds of aftershocks in the South Pacific country. It rattled frayed nerves in an area where memories of a deadly 2011 quake are still fresh.
Christchurch, the largest city on New Zealand's ruggedly beautiful South Island, is still recovering from the 2011 quake, which measured 6.3 magnitude and killed 185 people.
Powerlines and telecommunications are down, and daylight revealed sizeable cracks in roads and damage to infrastructure after the original quake just after midnight shook New Zealanders from their beds.
"It was the most significant shock I can remember in Wellington," Prime Minister John Key told reporters at a dawn news conference from the parliament's underground bunker in the capital city. "There will be quite major costs around roads and infrastructure."
New Zealand's Geonet measured Monday's first quake at magnitude 7.5, while the U.S. Geological Survey put it at 7.8. The quakes and aftershocks rattled buildings as far away as the New Zealand capital, Wellington, 300 kilometers (185 miles) to the northeast.
Key said he hoped to travel on Monday to the tourist town of Kaikoura, about 150 kilometers (90 miles) northeast of Christchurch and which appeared to have borne the brunt of the quake.
New Zealand's Civil Defence declared a state of emergency for the Kaikoura region soon after Monday's large aftershock.
A tsunami warning that led to mass evacuations after the original quake was downgraded after large swells hit Wellington, in the North Island, and Christchurch. There were no new tsunami warnings issued after the 6.2 aftershock.
New Zealand lies in the seismically active "Ring of Fire", a 40,000 kilometers arc of volcanoes and oceanic trenches that partly encircles the Pacific Ocean. Around 90 percent of the world's earthquakes occur within this region.
Stock exchange operator NZX Ltd said markets were trading, although many offices in the capital were closed. The NZX said its Wellington staff were working remotely.
A flurry of listed property companies, including Investore Property and Argosy Property, issued notices to the NZX saying they were examining buildings for any damage. Initial inspections showed limited impact.
Key was meeting national emergency officials on Monday and postponed a trip to Argentina, where he had planned to hold a series of trade meetings ahead of the Asia-Pacific Economic Cooperation (APEC) leaders' summit in Peru this week.
"The situation is still unfolding and we don't yet know the full extent of the damage," Key said.
ALL BLACK HERO
St. John Ambulance said it was sending helicopters carrying medical and rescue personnel to Kaikoura, where at least one of those killed was found in a collapsed house. Two other people were pulled alive from the same building, disaster officials said. The South Island town, a popular destination for whale watching, was completely cut off.
New Zealand media reported one of the pilots was Richie McCaw, the recently retired captain of New Zealand's world champion All Blacks rugby team.
Kevin Heays, of Environment Canterbury in Kaikoura, told Radio New Zealand there had been a lot of damage to roads.
"There are a lot of poles down," he said. "I'd say we will be without power for a long, long time. I understand that the roads north and south are out so we are pretty well isolated."
New Zealand television reported that water to the town had also been cut off. A photographer about 60 kilometers (37 miles) from the town reported damage to roads, bridges and railway lines.
Residents in Wellington caused gridlock on the roads to Mount Victoria, a hill with a lookout over the low-lying coastal city. Around 100 people, including children sleeping on floors and benches, were camped out in the distinctive parliament "Beehive" building.
"I never thought I would go to a parliament in my pajamas," said German tourist Agatha Blasinski, 35, who had been sleeping in a Wellington backpackers' hostel when the quake struck.
Residents were advised to stay away from the central business district on Monday and the train network was closed for checks. Wellington International airport was open, however, although some arriving and departing flights were delayed.