SYDNEY, Dec. 21 (Xinhua) -- With thousands of passengers trying to get home for Christmas, weather disruptions and a system outage, Australia's Sydney airport was under increased pressure and saw extended queues "out the door."

Heavy storms battered the city on Thursday leading to a number of flights being cancelled and passengers redirected to fly the next day.

Extra passengers, as well as the temporary malfunction of a passport processing system, meant long delays as services at the airport came under pressure.

Virgin Airlines Australia posted on their social media account that "it's incredibly busy at the airport -- we're doing our best to get everyone on their way as quickly as possible after last night's storm."

Passengers told the Herald that "lines were snaking outside the terminal" and that "everyone is looking a bit bored and irritated."

"It was the best and worst of humanity," one passenger said. "I saw people in tears, there were people pushing in and a very understaffed desk."

Given the time of the year, and the interruption of the storm, airport officials said delays were to be expected.

They are urging passengers to check with their airlines as to the ongoing status of their flights.