An earthquake shook Canterbury early on Tuesday morning.
The 5.3 magnitude tremor - one of the strongest aftershocks since the February earthquake - struck at 3.04am.
The quake was centred 20 kilometres west of Christchurch and was at a depth of 15 kilometres.
Bishopdale resident Pauline Saggers says it was a very violent jolt.
Police and the Fire Service said they had no reports of damage.
GNS Science says the quake would have been felt widely around the region.
It says such aftershocks are expected in the wake of the February quake, and though the number will decrease, Christchurch will still get the occasional violent shake.