Police have condemned the actions of a person they believe climbed a fence at Dunedin Airport and left a bag along with a panic-inducing note.
The airport was partially closed on Sunday evening after a black laptop bag was found in an observation area of the airfield.
Two Monday morning flights were cancelled as the NZ Defence Force secured the scene and made the bag safe.
Now police are appealing for information as they investigate the hoax.
It's believed the culprit scaled a set of external fences on Centre Rd between about 11:30am and 6:15pm on Sunday.
They left the bag in an area in which people often park to watch planes landing and taking off. They also left a written note with the item which gave officials reason to believe the bag could pose a credible threat.
New Zealand has been on a high terror alert for the first time in history since Friday's attacks, and police around the country are treating potential security threats with extra caution.
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"The insensitive nature of this act in light of recent events cannot be overstated," a spokesperson said.
"A large number of people were disrupted and distressed as a consequence."
Police want to hear from anyone who saw suspicious activity around Dunedin Airport on Sunday.
Anyone with information is urged to contact Dunedin Police on 03 471 4800, or Crimestoppers anonymously on 0800 555 111.
In the aftermath of the Christchurch shootings, Auckland Police evacuated Britomart train station and later carried out a controlled explosion of unattended luggage.
On Monday police responded to a bomb threat made by a passenger in Auckland Airport's domestic terminal, which later turned out to be a "misunderstanding".