New Zealanders have described how people were left screaming and crying after Christchurch was hit by a "seevre" 5.8 magnitude quake on Sunday.
There were no reports of serious damage or deaths, but the tremor brought back memories of the 2011 tragedy in which 185 people were killed.
The New Zealand Herald described the incident as a "major psychological blow" for a region still trying to recover from the disaster.
Jacob Savage, 17, was in a supermarket in Christchurch when the earthquake started.
He told the New Zealand Herald how the quake caused a roof to collapse and people were left screaming and crying. He said he grabbed a little girl near him and they curled up into a ball until the tremor stopped.
A woman in her 60s is reported to have suffered a heart attack.
Mr Savage said: "I've done a first-aid certificate and so I knew what to do. I ran to get a staff member and called 111 and I put her in the recovery position, then I stayed with her until the ambulance came."
Others tweeted images of the scene around the city.
A spokesman for Sumner Surf Life Saving Club told AAP that everyone was "a bit freaked out".
St John’s Ambulance service said no-one was killed in the quake, but several were hurt while trying to run away from buildings.
The earthquake came close to the anniversary of the 6.3 magnitude quake that destroyed much of New Zealand’s second largest city.
No tsunami warning was issued and the quake was a shallow one at just five miles deep. However, New the seismological body GNS Science classified Sunday's earthquake as "severe".
Earthquakes are common in New Zealand, which sits on the “Ring of Fire”, an area of intense seismic activity.