Around 1,400 passengers of the Polish airline LOT were left grounded at Warsaw Chopin airport over the weekend after hackers attacked the airline's computer systems used to issue flight plans.
The computer system was hacked on Sunday afternoon and was out of action for around five hours.
During that time, 10 of the airline's national and international flights were cancelled, and around a dozen delayed.
The BBC reports that flights were getting back to normal on Sunday night, and that flights to Dusseldorf, Hamburg and Copenhagen and Polish cities were affected.
Spokesman Adrian Kubicki told the Guardian that the airline provided hotels for those that needed to stay overnight, and also added that at no time was the safety of ongoing flights compromised.
He added: "We're using state-of-the-art computer systems, so this could potentially be a threat to others in the industry."
Reuters reports that the attack is now being investigated by authorities, and that the airport itself was not affected.