Beijing : A 6.8-magnitude earthquake jolted the sea off the South Island of New Zealand Sunday, the China Earthquake Networks Centre said.
The epicentre, with a depth of 10 km, was monitored at 41.7 degrees south latitude and 174.5 degrees east longitude, reports Xinhua.
Earlier, a 5.8 quake struck the same region Sunday morning followed by a series of smaller quakes throughout the day.
New Zealand government geological agency GNS Science said the 6.8 magnitude quake occurred at 5.09 p.m. (5.09 GMT) and was centred 30 km east of Seddon near Blenheim at a depth of 17 km. The 5.8 quake at 7.17 a.m. was also centred near Blenheim at a depth of 19 km.
GNS Science described both quakes as severe, adding that more aftershocks can be expected. Civil Defence said so far no reports of injures had been reported.
All train services around Wellington were suspended after the quakes and TranzMetro said delays can be expected.
A magnitude 5.7 earthquake occurred beneath Cook Strait Friday. It was 8 km deep and lasted for about 20 seconds.