Moderate earthquakes have rattled the lower South Island.
A magnitude 5.5 quake occurred at 10.01pm on Thursday and was centred at sea, 190km south-west of Tuatapere at the bottom of the South Island at a depth of 12km.
Earlier, a 5.8-magnitude tremor was felt at 7.48pm in the same vicinity and also at a depth of 12km.
They were followed by a 5.0 quake at 1.46am on Friday, at a slightly deeper 20km.
Sergeant Deon McNaught, of Invercargill, says the first tremor seemed to last about 30 seconds.
"We could see anything that wasn't tied down was shaking from side to side - nothing to cause any alarm, but it was quite noticeable."
Mr McNaught says there had been no reports of damage on Thursday night.
The Geonet website is reporting that the 5.5 quake was felt widely throughout the South Island, including Bluff, Tuatapere, Dunedin, Alexandra, Christchurch and as far north as Kaikoura.
GNS Science seismologist Lara Bland says the earthquakes early were generated in the Fiordland subduction zone where some of New Zealand's biggest earthquakes have been felt.
A 7.8-magnitude quake in Dusky Sound, also in western Southland, on 15 July 2009 was the biggest since the devastating Napier earthquake in 1931.
The Dusky Sound quake caused little damage, however.
