Australia’s national cyber security coordinator said the “large-scale technical outage” was caused by an issue with a “third-party software platform”, allaying initial fears of hacker involvement.

Photos posted online showed large queues forming at Sydney Airport, which told AFP some airline operations and terminal services had been affected.

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“Flights are currently arriving and departing however there may be some delays throughout the evening,” a Sydney Airport spokesman said.

“We have activated our contingency plans with our airline partners and deployed additional staff to our terminals to assist passengers.”

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Christchurch International Airport in New Zealand similarly said it was “experiencing IT issues across a number of our systems which may affect flight arrivals and departures”.New Zealand said banks and the computer network inside the country’s parliament had also been affected.

Australia national broadcaster ABC said its systems had been crippled by a “major” glitch, derailing some television and radio broadcasts.

Some self-checkout terminals at one of Australia’s largest supermarket chains were rendered useless, displaying blue error messages.

Telecommunications firm Telstra said some of its systems had been disrupted, possibly impacting emergency services that used its network.

Telstra said it was caused by “global issues” impacting software provided by Microsoft and American cyber security company Crowdstrike.

Microsoft and Crowdstrike could not immediately be reached for comment.

University of South Australia cybersecurity researcher Jill Slay said the global impact of the outages was likely to be “enormous”.