A shallow 4.2 magnitude earthquake has been detected near East Cape, after a strong aftershock near Wellington this morning.
This afternoon's tremor, at 2.16pm, was centred 55km east of Tokomaru Bay at a depth of nine kilometres, GeoNet reported.
It rated six for Mercalli Intensity - the power with which it was felt on the Earth's surface.
There were no immediate reports of damage.
It followed this morning's strong aftershock in the swarm of quakes affecting the area south of Wellington.
The magnitude 4.9 event occurred at 11.10am and was centred 30km east of Seddon in Marlborough at a depth of 16km.
Twitter users reported the incident:
That was a big one! #eqnz— Holly Walker (@hollyrwalker) July 31, 2013
Here we go again - more shakes— Peter Dunne (@PeterDunneMP) July 31, 2013
decent little tremor in Wellington just now #eqnz— Peter Griffin (@petergnz) July 31, 2013
Damn it, wish I didn't keep feeling like I should be diving under my desk. #eqnz— Pipssqueaks (@Pipssqueaks) July 31, 2013
Was I the only one that got under my desk at work? #EQNZ— Jo Orange (@jo9ty) July 31, 2013
Over the past couple of weeks, being at work has felt rather like being in a plane going through mild turbulence. #eqnz— Kiwichettan (@BarnabyHM) July 31, 2013