CANBERRA (DPA) - An e-gate system outage at every international airport in Australia caused long delays for passengers departing and arriving in the country on Monday (April 29).

The Australian Border Force (ABF), which is responsible for immigration and customs security, said it was working to resolve the "IT systems outage".

"Additional ABF staff have been deployed to process passengers and to minimise delays. Passengers are encouraged to arrive at airports early to allow additional time for processing," the ABF said in a statement.

Social media users reported and shared images of long queues at airports across Australia.

"Electronic customs machines not working, was hot & people getting cranky & pushy," passenger Lisa McLean said on Twitter of the situation at Sydney Airport.

Television chef Adam Liaw said on Twitter that despite being told by staff it would take one to two hours to get through passport control, it took him "more like 40 minutes".

Brisbane Airport said the computer systems outage was affecting all electronic passport gates.

"We've had about 10,000 people due to arrive or partially arrived already at Brisbane Airport because this is the exact time when all of the internationals come in," Brisbane Airport Corporation spokesman Leonie Vandeven told ABC Radio.

One passenger told 3AW radio in Melbourne that immigration officials were manually processing everyone, causing long delays at the city's main airport.

"About four planes have landed, I reckon there are 500-600 people here," she said. "It's just ridiculous."