An Australian Border Force system outage has caused delays at international airports across Australia.
Passport control machines were down at Sydney, Melbourne and Brisbane international airports, causing lengthy delays on Monday morning. More airports around the country could be potentially affected by the issue.
Travellers complained of extensive delays, with photos posted on social media showing large queues snaking throughout terminals.
A Brisbane Airport Corporation spokeswoman said the airport was first notified about the SmartGate passport machine issue just after 6am.
"The ABF smart gates were in and out and they were doing manual processing at the international terminal," she said.
"We got staff in pretty quickly to manually process people."
An ABF spokesperson said the ABF was working with the Department of Home Affairs "to resolve an IT systems outage impacting inbound and outbound passenger processing at international airports".
"Additional ABF staff have been deployed to process passengers and to minimise delays," the spokesperson said in a statement.
"Passengers are encouraged to arrive at airports early to allow additional time for processing."
ABF controls the SmartGate passport machines, which use facial recognition technology along with ePassports to check travellers' identities.
While the ABF spokesperson did not say which airports were affected, SmartGates are installed at Sydney, Melbourne, Brisbane, Adelaide, Cairns, Canberra, Gold Coast, Darwin and Perth airports.