Mystery surrounds the origins of a loud rumbling noise heard in the wider Wanganui region overnight.
The noise happened between 10.15pm and 10.30pm and was heard from Turakina to Waitotara.
It was loud enough to shake the ground in Ratana Pa and reportedly set off the civil defence siren there.
The topic was being discussed widely on social media, including on the Wanganui Chronicle's Facebook page.
Doreen Barns said she heard it in Putiki, and thought it was an earthquake. "It was extremely loud, it started with a loud bang followed by a rumble."
Piri Rurawhe said everyone had felt the shaking at Ratana Pa.
"It felt like something [had] hit the house," Mr Rurawhe said.
A spokesman for GeoNet, which records earthquake, tsunamis and volcanic eruptions, said the organisation's recording instruments had been quiet overnight.
"Just after 10pm there was a tiny earthquake that was so small it couldn't be felt or even located accurately," the spokesman said.
There were similar reports of loud noises in Auckland last year, which turned out to be caused by the military.
"Even if that was the case [with last's night noise] I would have expected our instruments to have picked it up," the spokesman said.