SYDNEY (REUTERS) - Sydney Airport said on Friday (March 9) a technical snag caused interruptions in passenger processing at two of its terminals, causing hours of delay for travellers.

Photos and videos of the airport showed uncomfortably long queues as passengers crowded the terminal as a result of the outage.

The airport has now resumed processing passengers as per usual, it said on Twitter, without specifying details of the problem. "We are working hard to catch up any delays," it said.

The glitch affected outbound flights from its international terminal and one of its two domestic terminals. Inbound flights were not affected.

Qantas Airways Ltd, the country's biggest carrier, said it was not affected as it operates out of a different terminal.

Virgin Australia Holdings Ltd, the country's No. 2 carrier, expected "some impact" to its flights as it works "to minimise any disruption to passengers ... and to reaccommodate any affected passengers."

A technical issue with an air traffic control system had briefly grounded flights at the Sydney Airport last September (2017).

Sydney is Australia's busiest airport, generating A$30.8 billion (S$31.6 billion) in economic activity each year, according to its website.