A group-wide IT system failure at Lufthansa has stranded thousands of passengers, which the German airline blamed on underground engineering works at a railway station in Frankfurt cutting several fibre optic cables.
Repairs would take until this afternoon according to Lufthansa, citing information it had received from Deutsche Telekom.
It expects flight operations to stabilise by early evening.
Photos and videos from several German airports showed thousands of passengers waiting to be checked in.
Shares in Lufthansa, which also owns SWISS, Austrian Airlines, Brussels Airlines and Eurowings, were down 1.25% at 11.44am GMT.
Passengers said on social media the failure had forced the company to organise the boarding of planes with pen and paper and that it was unable to digitally process passengers' luggage.
In a tweet, Lufthansa said: "As of this morning the airlines of the Lufthansa Group are affected by an IT outage, caused by construction work in the Frankfurt region."
⚠️Important information on flight disruption: As of this morning the airlines of the Lufthansa Group are affected by an IT outage, caused by construction work in the Frankfurt region. Unfortunately, this has led to flight delays and cancellations. We are working on -
— Lufthansa (@lufthansa) February 15, 2023
According to the Frankfurt Airport website, reports of Lufthansa flight disruptions started from around 7am GMT and about 120 in and outbound flights at the airport were cancelled.
Frankfurt Airport said it will cancel or divert all incoming flights to the airport.
German air traffic controllers said Lufthansa planes could no longer depart from Frankfurt Airport and were parked there, meaning no parking positions were available for other aircraft.
Please check the status of your flight before traveling to the airport and allow extra time for your journey. We also recommend that you check in as early as possible for your flight. https://t.co/fH6Q1xbqbh
— Frankfurt Airport (@Airport_FRA) February 15, 2023
Bloomberg News said Lufthansa had grounded all of its flights but the company told Reuters it could not confirm that.
"There are still flights in the air, they will not be brought to the ground," a spokesperson for the company said.
Data from aviation website Flightradar24 showed Lufthansahad 40 flights in the air at 1023 GMT, compared with 105 flightsof rival national airline of Air France and 121 of BritishAirways.
Germany's federal cyber agency BSI was not immediatelyavailable for comment.
The IT system failure comes two days ahead of plannedstrikes at seven German airports that are expected to lead tomajor disruptions, including potentially at the Munich SecurityConference where world leaders are expected to gather.
Scandinavian airline SAS said it was hit by a cyberattack on Tuesday evening and urged customers to refrain fromusing its app, but later said it had fixed the problem.
Unknown attackers cut cables belonging to Germany's publicrailway in December in what was seen as a second act of sabotageagainst Deutsche Bahn in as many months.
Airlines cancelled more than 1,300 flights and over 10,000were delayed in the United States last month after the breakdownof a key government computer system.
