Christchurch has had another moderate earthquake, followed by more aftershocks.
The magnitude 5.0 quake occurred at 2.47am on Sunday. It was centred 10km east of Christchurch and 10km north-east of Lyttelton, at a depth of 9km.
The quake was followed by magnitude 3.0 and 3.7 aftershocks at 4.11am and 5.10am and magnitude 3.3 and 3.5 at 7.05am and 7.48am.
Later aftershocks included a magnitude 3.5 at 10.28am, a magnitude 3.8 at 4.40pm and a magnitude 3.7 at 8.31pm.
The ambulance service says there are no reports of damage or injury.
There was a magnitude 4.6 earthquake at 8.56pm on Thursday, with a number of lesser quakes since then.
GNS said on 6 January that aftershocks might continue in Canterbury for the next 30 years.