This follows a morning of dramas at Sydney Airport following a technical glitch which caused major flight delays to T1 and T2 terminals.
"We're working to resolve the issue as quickly as possible and thank you for your patience".
A technical issue with an air traffic control system had briefly grounded flights at the Sydney Airport last September.
"We're advising passengers and visitors to avoid T1 and T2 until further notice".
Would-be commuters were left stuck at check-in early on Friday morning after a technical issue resulted in the security screening being unable to open.
"Our terminal staff are on hand to provide updates".More news: Committed to winning back trust of people in northeast, says Rahul Gandhi
Virgin Australia said that "due to a technical issue" passengers were being processed at reduced capacity.
Almost 16 million of those were worldwide passengers, with those from China being one of the major sources of travellers, according to airport figures.
The T3 Domestic terminal, which is operated by Qantas, was not affected. "We are working hard to catch up any delays", it said.
The security screening has also been closed as Queensland Police investigate the matter.
It affected systems including the airport's CCTV, meaning passengers could not be screened for about two hours.
Passengers said they had been waiting for nearly two hours as the departure lounge was cordoned off.