A technical fault had some North Island residents in a tsunami panic overnight.
Police say they received reports of sirens sounding across the East Coast and Bay of Plenty on Sunday evening.
"The tsunami sirens are going off from Waihi to Papamoa along the whole [Bay of Plenty] coast, been going for 15mins," one resident told Newshub in an email.
"People all panicked at the moment."
Another person, on Twitter, said it sounded "like chaos".
"How can people have any trust in a system like this?"
The National Emergency Management Agency said it doesn't operate tsunami sirens in some of the affected areas.
Civil Defence Bay of Plenty said the siren song was due to a Fire and Emergency system fault.
"Fire and Emergency New Zealand understands a number of sirens were activated along the Bay of Plenty coast this evening, including some at our stations," Fire and Emergency later confirmed.
"We are focused on working alongside our partner agencies to find out what caused these sirens to activate. The activation was an error and there was no danger to the public.
"We will continue to look into the matter later in the morning."
A post on the Te Puke Fire Brigade Facebook page showed a computer screen showing a tsunami report.
"This evening our station siren along with neighbouring brigades all activated signalling everyone to a Tsunami Warning," the post said.
"We have just had confirmation that this was indeed a system fault. Fire & Emergency will be investigating this issue as to why this occurred. We apologise for the inconvenience please rest assured there is no need to panic."
