Due to a Lufthansa IT glitch, all flights have been diverted from Frankfurt to non-destination

Germany’s air traffic control agency said Wednesday it will divert all flights from Frankfurt, the country’s busiest airport, after a problem with Lufthansa’s computer system caused major disruption to German airlines.

Agency spokesman Robert Ertler said all of the plane’s parking lots in Frankfurt were full because passengers and crew were unable to board the airline’s flights.

“All incoming flights are being diverted to alternative airports such as Munich, Nuremberg and Düsseldorf,” Eltler told the Associated Press.

The Lufthansa Group, which includes subsidiaries such as Swiss International Air Lines and Eurowings, said construction work in the Frankfurt area caused an IT outage.

“This is causing flight delays and cancellations,” the company said. “We apologize for the inconvenience caused to our customers.”

Telco Deutsche Telekom later confirmed that the excavator cut the fiber optic line at a depth of 5 meters (16 feet) while working on the railroad tracks.

The company said some of the damaged lines had already been repaired and the situation was expected to improve significantly on Wednesday afternoon, German news agency dpa reported.

All domestic Lufthansa flights have been canceled and passengers have been asked to switch to alternative modes of transport, such as trains, according to dpa.