"Around nine o'clock, pilots made a suspicious observation," said Stefan Bayer, a police spokesman, to the newspaper Bild.
According to Bayer, a potentially unauthorized flying object was observed near the airport, which could be a drone.
A large police operation, including a helicopter, was deployed to investigate the area around the airport.
For safety reasons, all flight operations were suspended, but after an hour, air traffic was able to resume as no suspicious object could be detected.
This is not the first time the airport has been closed after a drone alarm. In early October last year, air traffic was halted and thousands of passengers were forced to spend the night at the airport.
