An Australian Border Force security outage has caused lengthy delays in airports across the country.
Passport control machines are reportedly down in Sydney, Melbourne and Brisbane international airports, with thousands of passengers experiencing massive queues at immigration.
A spokesperson from the Australian Border Force told news.com.au they are working to resolve the issue, and advised passengers to arrive at airports early for additional processing time.
"The Australian Border Force (ABF) is working with the Department of Home Affairs to resolve an IT systems outage impacting inbound and outbound passenger processing at international airports," a spokesperson said in a statement.
"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."
Angry passengers have taken to social media to vent their frustration over the outage, which is reportedly due to the SmartGate immigration system failing.
"45 min in "line" an hour to go? Worst mess I've seen," one person said on Twitter.
"Sydney airport you should be ashamed," another added. "7am, all the international flights are landing, the epassport gates aren't working and 2000 people are jammed into your poxy arrivals hall."
"The SmartGate system is down at Sydney Airport and there are THOUSANDS of passengers waiting in line to be processed manually. This is going to take HOURS," another said.
Another Twitter user said "emergency supplies" were being rolled out to keep passengers hydrated.
One passenger told news.com.au that each passenger was being manually processed through immigration after the system went down just after 6am.
The SmartGate passport systems work using facial recognition technology to check travellers' identities.
News.com.au has contacted the Australian Border Force and Sydney Airport for comment.