A lengthy queue at Auckland Airport's domestic terminal on Tuesday morning was caused by upgrades to a security machine.

The Aviation Security Service has closed one of its five security lanes until 5 December to install a new scanning machine.

A large number of arrivals, many for Wednesday's Coldplay concert, caused a large queue to form at around 6am.

The queue started to clear by 7am, it said.

Avsec said it was reviewing CCTV footage and working with Auckland Airport to improve passenger flow.

Meanwhile, Air New Zealand has had to add 22 more flights to Auckland as thousands of Coldplay fans visit the city.

The first of three concerts will be held at Eden Park on Wednesday evening and is expected to draw a crowd of 50,000.

Air New Zealand said it was shaping up to be one of its busiest weeks of the year for the domestic network, with more than 230,000 customers expected.

Friday was set to be the busiest day, with 40,000 passengers in the sky, it said.