Around 1,400 passengers flying on the Polish state airline LOT have been stranded after hackers attacked its ground computer system at the Warsaw Chopin Airport.
Ten LOT flights to Dusseldorf, Hamburg, Copenhagen, and Polish cities were cancelled and 12 delayed on Sunday, as it took nearly five hours to rectify the technical problems.
Hackers had attacked the computer systems that are used to issue flight plans. Authorities are investigating the matter.
LOT Adrian Kubicki said that the journey of passengers who were already onboard the flying flights was not affected. Its services from other airports, too, remained unaffected.
"We're using state-of-the-art computer systems, so this could potentially be a threat to others in the industry," Kubicki added.
In the first week of this month, the entire fleet of United Airlines was grounded in the US for a mysterious reason, before they were allowed to fly after almost an hour.
Though the airline claimed that the flights were grounded due to some issue with dispatching information, pilots have reportedly told the passengers about a possible hack of the computer systems resulting in the dispatch of faulty flight plans.
A tweet by one of the passengers Ted Benson read: "Sitting on runway. Pilot inferring #UnitedAirlines has grounded all flights due to possible hack: fake flight plans found in system."
The US Government Accountability Office (GAO) said in April that the internet-based systems are making modern aircraft increasingly vulnerable by providing hackers remote access to in-flight avionics systems.
The GAO report said: "Cyber-based threats to federal information systems are evolving and growing.
"The growing interconnectivity among information systems presents increasing opportunities for cyber attacks."
Image: Ten LOT flights to Dusseldorf, Hamburg and Copenhagen, and Polish cities were cancelled. Photo: courtesy of Warsaw Chopin Airport.