Stock on the floor at New World supermarket in central Wellington. Photo/ Twitter user Mika Reilly
Wellington and the top of the South Island have been hit by a 6.5 magnitude quake this afternoon.
Did you feel the quake? Send your story, photos or video here.
The quake, which was centred 30km east of Seddon, the site of all the seismic activity in the last couple of days, was 11km deep.
"That's the worst quake I've ever felt,'' said Wellington resident Sarah Bennett.
Ms Bennett and her husband Lee Slater, whose Highbury house is built on the side of a hill, said it was swaying on its piles.
"You usually only get a bit of a jiggle but this was a hula dance,'' Ms Bennett said.
Mr Slater said he was in shock.
Deborah Parsons, who lives in Blenheim, felt the quake and said it was scary.
The contents of her china cabinet had smashed on the floor.
"I'm getting the energency kit ready and I'm packing up what's left of the china,'' she said.
The shake was immediately followed by smaller quakes in around the Wellington/Cook Strait area.
This afternoon's large shake, which struck just after 5pm, followed dozens of aftershocks after this morning's magnitude 5.8 in Cook Strait between Wellington and Seddon at 7.17am.
Most of the tremors have been centred in the strait but there have been quakes further south off Kaikoura and as far north as Wanganui.
A magnitude 5.7 quake shook the region on Friday.
Social media users were quick to report their experiences of the quake.
"Felt in Te Awamutu,'' said one Twitter user. "Trees were rocking and hanging plants swaying - felt seasick.''
Another said: "They are coming in on waves''
A woman from the 10th floor of a central Wellington building ran out and left in her car, saying the city centre wasn't a safe place to be.
A picture posted on Twitter showed windows shattered in the Quest Apartments in Hunter St in the city.
Office worker Alice Midgley was on the 13th floor of the Fujitsu building.
"I was under the desk, that was the first time I was frightened,'' she said.
Glass from broken windows had fallen onto Lambton Quay and street workers were keeping people away from this buildings in case another quake struck and loosened the glass that was left.
Wellington airport spokesperson Briarley Kirk said the runway would be closed for about 20 minutes for a routine inspection.
"They will inspect the runway to ensure it's all in working order.''
She was unable to say how many flights were affected
One person said on Twitter that there was a ``serious water leak'' at the city's library and that fire engines were arriving.
The Pacific Tsunami Warning Centre (PTWC) said Civil Defence had made an initial assessment that the earthquake was unlikely to have caused a tsunami that would pose a threat to New Zealand.
Photos posted on Twitter and Facebook showed damaged walls, broken belongings and swinging lights.
New Plymouth resident, Michael Riley, told the Herald that ``everything was moving'' in his Taranaki home.
"There was 20 seconds of shaking, everything in the room was moving,'' he said. "I went outside and still all the power lines were shaking and it was just chaos, it was quite scary. It was the biggest earthquake I have ever felt.''
Andrew Feldon said: "Felt it here in Hastings! Kept going for ages - was watching the trees outside the window swaying.''