Thousands of shocked people wandered rubble-strewn Christchurch, many searching for loved ones and trying to reach trapped people, after a major earthquake threw the city into chaos.
Screams rang out across the southern New Zealand city's main square as parts of Christchurch Cathedral toppled to the ground, while TV footage showed onlookers clinging to each other and others bleeding and limping.
As police reported fatalities, emergency workers rushed to free those trapped in several office buildings by the quake which buckled roads and rained debris on streets packed with lunchtime shoppers.
"They are going to come and get you down.
Just keep away from the edge," one woman yelled to a distraught colleague trapped on the top level of what had been a four-storey building, but which folded like a concertina.
The distressed woman was rescued by fire workers on a crane soon afterwards, and hugged her colleagues after reaching the ground which was littered with shattered glass, office paperwork and broken computers and desks.
But as more aftershocks hit the city, workers said they feared another four colleagues were trapped under concrete on one of the building's lower floors, as horrified office workers, some with bloodied heads, looked on.
"We are just worried about other colleagues. Just hoping that they are OK," one woman told TV3.
The 6.3-magnitude quake comes almost six months after a 7.1 tremor devastated the island nation's second largest city, weakening buildings.
"The (September quake) is nothing compared to this," one shaken man told New Zealand television as he surveyed the damage.
Television images showed residents hugging each other as they stood in the streets on Tuesday, gazing at cars, buildings and roads destroyed by the quake which hit at 12.51pm (1051 AEDT). "It's just a disaster," another person told TV3.
"There must be deaths this time." "It really and truly was horrendous," said one man, who was inside a central city restaurant when the quake hit.
Reports said the city had run out of ambulances to rescue the injured, and television footage showed a private four-wheel drive car being used to ferry away several injured workers.
"It's just huge. It's huge," said one witness, as he surveyed the wreckage of Christchurch's iconic cathedral.
