A powerful 7.3-magnitude earthquake struck off the coast of New Zealand today, triggering an early-morning tsunami threat on the shores of the Pacific nation.
New Zealand authorities have urged an evacuation in a 100-mile stretch of coast on the North Island, telling people to flee to high ground or 'as far inland as possible'.
High waters were expected to lash the coast shortly after 3am local time with a US monitoring service predicting 3ft waves and local disaster officials warning of an hours-long threat of 'unpredictable surges'.
Witnesses on the North Island described a 'very long, swaying shake' and houses making 'cracking sounds' in a tremor which some thought had lasted for as long as a minute, but there were no immediate reports of casualties.
'Hope everyone is ok out there - especially on the east coast who would have felt the full force of that earthquake,' prime minister Jacinda Ardern posted on Instagram.
This diagram shows where the earthquake struck off the coast of New Zealand on Thursday
New Zealand's emergency management agency told people living in a 100-mile stretch of coast to move inland or to high ground as soon as possible
More than 60,000 people reported feeling the quake on seismic monitor GeoNet, with a few hundred describing the shaking as 'severe' and 75 calling it 'extreme'.
There was no tsunami threat to Wellington and other regions, but civil defence authorities told people to stay away from beaches across New Zealand.
The 2.30am quake, which came less than an hour after a 3.7-magnitude rumble in the same area, was measured at 110 miles from the city of Gisborne. Aftershocks were still being recorded in the area.
Tsunami waves were possible within 180 miles of the earthquake's epicentre, the US-operated Pacific Tsunami Warning Centre said.
The Hawaii-based warning centre said in a 3am update that 'tsunami waves had been observed' following the earthquake.
New Zealand's disaster agency said shortly afterwards that flooding is expected in a 100-mile coastal stretch from Cape Runaway to Tolaga Bay.
New Zealand's prime minister Jacinda Ardern said on Instagram that she 'hopes everyone is ok out there' after the early-morning earthquake
The map shared by Ardern showing how many people had reported the quake in New Zealand, with more reports in darker-brown areas
'Tsunami activity will continue for several hours and the threat must be regarded as real until this warning is cancelled,' the emergency management agency said.
People in the affected stretch of coast should 'MOVE IMMEDIATELY to the nearest high ground, out of tsunami evacuation zones, or as far inland as possible,' it said.
'Strong and unusual currents and unpredictable surges near the shore are expected... this means a threat to beach, harbour, estuary and small boat activities.'
The evacuation advice overrides pandemic-related restrictions, it added, which were recently tightened again after a single new case of Covid-19 in the community.
New Zealand recently marked the 10-year anniversary of 2011's Christchurch earthquake which killed 185 people and wrecked large parts of the city.
This month also marks a decade since the Pacific earthquake that triggered the Japanese tsunami and resulting Fukushima nuclear disaster.