Tsunami sirens are being tested in Northland, Auckland and Christchurch on Sunday morning.
Sirens were being sounded at coastal and harbour locations along the east coast from Bland Bay in the north of Whangarei District southwards to Mangawhai Heads in the Kaipara District and in some locations in the Far North from just after 9am.
Christchurch's tsunami warning system was being tested at 11am.
Auckland Civil Defence Controller Clive Manley told Radio New Zealand's Sunday Morning programme it is important people know what the sirens sound like and how they should respond.
The sirens' sound varies in different parts of the country. In Auckland, coastal residents will hear a short siren first, which warns of an event, and a second tells people to get to higher ground.
Mr Manley said people should use the opportunity to think about what they would do if it was a real event.
