New Zealand PM John Key declares state of emergency after quake

New Zealand Prime Minister John Key today declared a national state of emergency confirming the death toll at 75 following the devastating earthquake that led to massive buildings and property damage around the country's second-largest city of Christchurch.

Around 55 bodies had been identified and there were a further 20 unidentified bodies, media reports said.

Another 400 people were listed as missing, though not all of them would be trapped in buildings that were being searched for survivors.

Rescuers have had to amputate limbs to free survivors from collapsed buildings after the quake, police said.

Superintendent Russell Gibson said bodies still littered the streets.

"There is incredible carnage right throughout the city," Gibson was quoted by media reports here.

"There are bodies littering the streets, they are trapped in cars and crushed under rubble where they are clearly deceased. Our focus has turned on the living."

Gibson said the number of trapped "could be another 100, it could easily be more than that", adding the toll would rise. "It will be significantly higher than that," he said. More than 500 rescuers, including police and military personnel, pulled between 20 and 30 people from the debris overnight, toiling through the darkness, he added. Overall, 120 people have been pulled alive from the rubble.

"It's quite amazing, we have some people we've pulled out and they haven't got so much as a scratch on them. We've had other people where we've had to amputate limbs to get them out," Gibson said.

Rescue efforts focused on the CTV building in Madras Street and the Pyne Gould Guinness Building in Cambridge Terrace, both of which collapsed.