Hopes were fading last night that any more survivors would be pulled from the rubble in Christchurch, as 300 people remained missing, including 100 feared dead in one building alone.
Police admitted dozens of victims were probably entombed in the collapsed Canterbury television building, described as "100 per cent unsurvivable". In a blow to families holding vigil for trapped relations, rescue operations inside the building were called off hours after 15 people were reported to have survived inside an air pocket under the rubble.
Officials warned the country to expect a significant rise in the number of casualties. Last night, the official death toll stood at 71, including a nine-month-old boy, with at least one Briton and an Irishman among the dead.
Despair was contrasted with dramatic stories of survival, including two women found alive after 24 hours. More than 120 people have been freed from destroyed buildings.
As New Zealand's second largest city was hit by more than 100 aftershocks, messages of support continued to flood in from world leaders, including US President Barack Obama, the Pope and the Dalai Lama. John Key, New Zealand's prime minister, declared a national state of emergency as rescue teams from around the world arrived in the city to help search for survivors.
Police said they were still holding out hope that people were alive in wrecked buildings. "Experts tell me that there are pockets within a number of these buildings, and providing people haven't been crushed there's no reason that we will not get people out," said Russell Gibson, a shift commander.
Military roadblocks were set up around the city centre after a curfew was imposed following outbreaks of looting. At least six arrests were made. Police also reported a rise in "domestic violence" as the trauma of the disaster took its toll. Thousands of people left homeless by the earthquake stretched emergency shelters -- set up in schools and sports grounds -- to breaking point.
More than 80pc of the city remained without power and running water, amid warnings about contamination from leaking sewage. Residents were urged to use their mobile telephones only to send text messages.
Estimates put the cost of rebuilding at more than e8.2bn.
Mr Key said New Zealanders' spirits would not be broken, but he warned that the final death toll could exceed that of the 1931 Napier earthquake, which claimed 256 lives. "Today all New Zealanders grieve for you Christchurch," Mr Key said in a televised address.
"We feel your pain, as only a small nation can, for none of us feel removed from this event."
Rescuers who had rushed into buildings immediately after the quake encountered horrific scenes.
A construction manager described using sledgehammers and chain saws to cut into the Pyne Gould Guinness building from the roof, hacking downward through layers of sandwiched offices and finding bodies crushed and pulverised under concrete slabs.
One trapped man died after talking awhile with rescuers, Fred Haering said.
Another had a leg pinned under concrete, and a doctor administered medicine to deaden the pain. A firefighter asked Mr Haering for a hacksaw. Mr Haering handed it over and averted his eyes as the man's leg was sawed off, saving him from certain death.
"It's a necessity," a shaken Mr Haering said yesterday. "How are you gonna get out?" (© Daily Telegraph, London)