New Zealand rescuers have 'narrow window' to save lives

Rescue teams have a "narrow window" of opportunity to save people trapped in the rubble from the earthquake which hit Christchurch, according to New Zealand's foreign minister.

Murray McCully thanked foreign countries for pledges of support and specialist rescue teams but warned that the death toll could continue to rise.

A national state of emergency has been declared by Prime Minister John Key following the 6.3 magnitude tremor.