A security breach at Auckland Airport caused disruption for travellers as all passengers had to be rescreened.
Flights were also delayed or cancelled as a result.
There have been reports of large queues at the domestic departures.
An Auckland Airport spokesperson said there was a security breach this morning.
It had now been resolved.
"Aviation Security Services is requiring all passengers to be rescreened and that process is underway now," the spokesperson said.
"We thank travellers for their patience and they should please check with their airline about any impact to their flight."
Air New Zealand said it had to cancel four flights as a result of the security breach.
Several other flighs were delayed.
"The team are working to reaccommodate any impacted customers and we thank them for their patience while we work to get them to their destination as quickly as possible," the airline said in a statement.
Earlier this month there were lengthy queues at Auckland Airport's domestic terminal caused by upgrades to a security machine.