The photo above shows collapsed buildings on Manchester Street, Christchurch. The tremor hit at 12.51pm local time (11.51pm GMT), about ten kilometres from the city.
It is an aftershock of the 7.1-magnitude quake that hit on 4 September. However, this one is more serious – that quake left two people seriously injured but did not cause any fatalities.
The death toll is expected to rise further; at least 200 people are believed to be trapped inside buildings or under rubble.
The prime minister, John Key, said: “We may be witnessing New Zealand’s darkest day.”
Helicopters are putting out fires caused by the quake and the military has been drafted in to help with the rescue effort. Australia has also offered specialist assistance.