A powerful 6.3 magnitude earthquake on Tuesday killed 65 people and trapped dozens more under flattened buildings in New Zealand's most devastating tremor in 80 years.
Frantic rescuers and bystanders dug for survivors and thousands of panicked residents rushed into the streets of Christchurch, just six months after a 7.0 quake weakened buildings in the southern city of 340,000.
Prime Minister John Key warned the death toll was likely to rise after the earthquake, which struck at lunchtime as streets were thronged with shoppers, and turned the city centre into a rubble-strewn war zone.
"The death toll I have at the moment is 65 and that may rise. So it's an absolute tragedy for this city, for New Zealand, for the people that we care so much about," Key told TVNZ.
"It's a terrifying time for the people of Canterbury," he said, referring to the region around Christchurch.
The city's iconic cathedral lost its spire, and the six-storey Canterbury TV building was reduced to a smoking ruin. Witnesses said 30 people had been trapped in a collapsed, four-storey office block which houses 200 workers.
Rubble and debris littered the city centre as dazed residents wandered past crushed vehicles, before the area was evacuated. Christchurch mayor Bob Parker declared a five-day state of emergency.
"This is about as bad as it gets," he said. "I think we need to prepare ourselves for a death toll that will be significant.
"I don't think we are talking about thousands but we are certainly talking about dozens of people who may not be able to be saved."
Local station TV3 said dead bodies had been pulled from a hostel and a bookshop, and a tourist was crushed to death in a van. All flights across the country were briefly suspended after a Christchurch control tower was damaged.
Power was cut to thousands of residents, mobile phone networks were disrupted and road and rail transport was badly hit after the violent tremor, which tore gaping fissures in asphalt.
Seismologists said the tremor was more damaging than September's quake, despite being smaller, because it was nearer to Christchurch's centre and much closer to the earth's surface.
The quake struck at 12:51 pm (2351 GMT Monday), five kilometres (three miles) from Christchurch at a depth of just four kilometres.
Video footage showed a landslide crushing a small building, while passersby fled for their lives from underneath a collapsing awning. Several strong aftershocks pummelled the stricken city.
Christchurch airport was closed and The Press building, a centre for newspapers, was badly damaged. Reports said trapped survivors were desperately texting their families from the wreckage.
The earthquake is the most deadly to hit New Zealand since a 7.8-magnitude tremor killed 256 people in the Hawke's Bay region in 1931.
On September 4, a 7.0 earthquake struck overnight, damaging 100,000 homes but miraculously leaving no one dead.
New Zealand sits on the "Pacific Ring of Fire", a vast zone of seismic and volcanic stretching from Chile on one side to Japan and Indonesia on the other.