Christchurch, New Zealand: A major operation swung into action on Wednesday with hundreds of foreign rescuers, equipped with sniffer dogs and cutting-edge technology, rushing to help New Zealand in its hour of need.
Teams from Australia, Japan, the United States, Britain, Singapore and Taiwan were to join hundreds of local rescuers digging through the rubble in Christchurch, where a 6.3 magnitude quake killed at least 75 people on Tuesday.
Japan, one of the world's most earthquake-prone countries, sent 70 rescuers equipped with fibre optic cameras and sound detectors, as well as sniffer dogs trained to enter confined spaces in the rubble.
About 300 people were still missing in the disaster, which struck while streets were busy with lunchtime shoppers and toppled buildings that withstood a 7.0-magnitude quake in September.
The Japanese team, which includes specialists from the coastguard, police and fire service, along with doctors and nurses, was due to arrive early Thursday and would be racing against the clock.
The first 72 hours after a quake hits is seen as the critical window for survival for those trapped by debris and rubble.
The rescuers are also equipped with aftershock warning devices and gas detectors, tents and portable toilets as well as food and medical kits, said a spokeswoman for the Japan International Cooperation Agency.
At least 23 Japanese citizens were among the missing, many feared trapped under the rubble.
Singapore donated the services of a military contingent that was in New Zealand before the quake struck, and sent a 55-strong disaster team.
Seventy-five American search-and-rescue specialists were due to arrive on Thursday, along with 63 from Britain while Taiwan sent a team it set up after a massive tremor hit the island in 1999, killing around 2,400 people.
The foreign help reaped dividends when Australian rescuers freed a woman Wednesday from the twisted wreckage of the four-storey Pyne Gould Guinness building, where she had spent the night hiding under her desk.
"New Zealanders are deeply humbled by the messages of support and offers of specialist search and rescue help that have flooded in over the past 24 hours from other countries," said Foreign Minister Murray McCully.
"Support will be critical over the next few days as we reassess the specialist services required to speed the rescue operation."
Australia was sending more than 140 specialist search and rescue personnel as well as medical staff and a 75-bed field hospital to provide emergency assistance. Some 300 police were also on their way.
"These police resources have been requested by the New Zealand government to support general duties police as part of the disaster recovery," Attorney General Robert McClelland said.
Time is of the essence for those trapped, with New Zealand's emergency management chief John Hamilton saying rescuers may have just two or three days to pull out anyone alive.
"We're reasonably pragmatic and understanding from international experience that there's a kind of window of opportunity which may only be open for about two or three days to effect a real rescue of people who have been trapped," Hamilton said.
"But we are also well aware that there are plenty of stories about how long some people do survive in the buildings."
About 30 people were rescued overnight as emergency workers dug through the rubble, sometimes using their hands.