An airport erupted in chaos after a fire alarm sparked a huge evacuation - but when operations returned to normal passengers were met with border queues lasting over one hour.

Gatwick Airport has pledged to carry out a "full internal investigation" after the incident which left elderly people with "nowhere to sit and no access to water" in the "gridlocked" passport control.

The Argus: Queues inside passport control at the airportQueues inside passport control at the airport (Image: Sandy Halse)

The alarm sounded on Monday evening in the North Terminal's baggage reclaim area with thousands spilling out of the airport.

But passengers waiting to pass through the UK border were locked inside "like cattle" while the suspected blaze was investigated.

The Argus: Gatwick's North Terminal is home to many of the airport's long haul flightsGatwick's North Terminal is home to many of the airport's long haul flights

It took disgruntled flier Tim Ross some 75 minutes to get his passport stamped after getting off his flight while Sandy Halse said even the e-gates were locked while the incident was ongoing.

A spokesman for Gatwick Airport told passengers at the time: "A fire alarm has been triggered in the North Terminal baggage reclaim area and passengers have been evacuated as a precaution. We expect to reopen the area shortly pending an investigation."

The airport spokesman added: "We will be carrying out a full internal investigation into the incident, which is what happens on every fire evacuation."