The "Verdi" labor union began an early warning strike this Thursday morning at Frankfurt Airport, the largest airport in Germany, along with 10 other airports.

The company "Fraport," which operates Frankfurt Airport, explained that boarding planes is currently not possible in Frankfurt; therefore, many flights have been canceled.

However, the German airline Lufthansa had previously announced that it would maintain most of its schedule at Frankfurt Airport, including long-haul flights.

Alongside Frankfurt Airport, travelers planning to travel to and from 10 other airports in Germany this Thursday will need to make alternative arrangements, as security staff at Hamburg, Bremen, Berlin, Leipzig, Düsseldorf, Cologne, Hanover, Stuttgart, Erfurt, and Dresden airports have also started a one-day strike expected to last until Thursday night.

Normal flight operations are expected to be possible starting tomorrow, Friday.

According to estimates by the German Airport Association, the strike is expected to cause the cancellation or delay of around 1,100 flights across Germany, affecting approximately 200,000 passengers, according to estimates.

Verdi union had started its strike late Wednesday evening at Cologne/Bonn Airport, where the night shift for passenger screening was not operated, according to Verdi. The participation rate there was 100%, according to the union spokesman Uzay Tarim.

He said: "It was a successful start to the strike."

About 80% of the scheduled flights today, Thursday, at Cologne/Bonn Airport were canceled, according to the airport’s website in the early hours of Thursday morning. Tarim expected this percentage to increase during the day.

At the airports of Berlin, Hamburg, and Stuttgart, all departures were canceled.

At Düsseldorf only one-third of the flights were canceled.

Tarim criticized the fact that a security company at Düsseldorf Airport offered to pay an additional amount of 200 euros (216 dollars) to encourage employees to come to work despite the strike.

He considered such a "strike-breaking bonus" provocative.

The Verdi union had called for a strike by private aviation security company workers at 11 major airports in Germany amid collective bargaining negotiations between employers and workers.