(file image) Photo: RNZ / Samuel Rillstone
Flights have had to be delayed after an evacuation in Auckland International Airport's control tower on Monday afternoon.
The alarm was triggered just before 2pm, restricting aircraft movements in Auckland.
The air navigation service provider, Airways New Zealand, apologised to passengers for the delays.
It said five planes were able to arrive or depart during the 35-minute evacuation, but a number of others experienced delays.
Management of air traffic was diverted to the Christchurch air traffic control centre during the evacuation.
It said there was no fire and was investigating what triggered the alarm.