Christchurch was jolted by a 4.2-magnitude aftershock this evening.
The aftershock struck at 7.08pm, according GNS Science.
It was located 20km southeast of Christchurch, at a depth of 9km, Stuff reports.
GNS said the quake was "strongly felt" in Christchurch, while several Twitter users described it as "violent" and "bloody sharp".
Aftershocks continue to shake the city, which has experienced 10 measuring 3.0 or greater in the area in the past week.
