A series of earthquakes have rocked Christchurch, East Cape and Taranaki over the weekend.
The latest was a magnitude 5 quake that struck an area 20km south of Hawera in the Taranaki this afternoon.
It followed an earthquake 15 minutes earlier centered 20 km south-west of Tolaga Bay.
The 3.6 magnitude quake happened at 1.20pm and had a depth of 21km.
A magnitude 4.6 earthquake shook Christchurch last night - the strongest aftershock since July, said GNS.
The quake struck at 9.15pm about 15km south-west of the city at a depth of 12km.
More than 3300 people had reported feeling the Christchurch quake to GeoNet by 8am today.
Dozens took to social media after the quake.
"Made me run out the door felt like it was going to get bigger the way it started looked like it was at Rolleston,'' @Kadin16 said on Twitter.
"I was in my office at the university enjoying my study, all of a sudden I found my self under the desk," @abbadalshalahi said.
A GNS spokesman said he had not heard any reports of damage.
There was a further magnitude 3.6 quake west of the city at 7.09am today.
GeoNet said the quake occurred 15km east of Methven at a depth of 6km.
Quake expert Mark Chadwick said last night's shake was widely felt, and Cantabrians should prepare for aftershocks similar to this morning's rumble.
"I'd expect to see some aftershocks from this one.
"Probably in the magnitude 3 type range - they tend to last maybe a few more days (in terms of) aftershocks."
- APNZ with Newstalk ZB