About 2,000 passengers at Adelaide Airport had to be re-screened this morning after a walk-through security detector failed.

The incident is said to be unrelated to another security breach which occurred at Melbourne Airport this morning.

The Adelaide terminal was evacuated just after 10am when it was discovered that the equipment had failed about half an hour earlier.

Screening recommenced shortly after.

"We do apologise for the impact that did have on a number of our customers," Adelaide Airport managing director Brenton Cox said.

"There were around about 10 delays, but fortunately it was actually fabulous.

"People were incredibly understanding, incredibly kind; we had a great bunch of customer care teams in their pink vests to help people out this morning through what was an unfortunate situation, but we think it was managed well in the circumstances."

Mr Cox said about 10 people went through unscreened and "a handful of those" were not able to be located.

"Hence the immediate concern around locating individuals," he said.

Traveller Jo De Silva said it had been a chaotic morning, but the situation had calmed down now.

"Everyone was pretty stressed when it happened, that their flights would be cancelled," Ms De Silva said.

"There's a feeling of relief now.

"I’ve just boarded my plane which is a relief because I have an important meeting interstate tomorrow."