A Border Force IT outage has caused chaos and delays at Australian airports.

“The Australian Border Force is working with the Department of Home Affairs to resolve an IT systems outage,” a Border Force spokesperson told tech news outlet iTnews on Monday.

“The outage is impacting outbound and inbound passenger processing at international airports.”

Agencies had reverted to manual processing of passports at the time of the last update.

Additional staff were sent out “to help minimise delays”, the spokesperson said.

“Passengers are encouraged to arrive early to allow additional time for processing.”

The cause of the outage is still unclear.