Security workers at most major airports in Germany began a one-day strike today, Thursday, to increase pressure for higher wages, causing disruption to air traffic.

The American network "ABC News" reported that all departing flights were canceled today from Berlin, Hamburg, and Stuttgart, and about four-fifths of flights in Cologne and a third of flights in Düsseldorf were also canceled.

The Verdi union for service workers in Germany had called on workers to strike at 11 airports: Frankfurt, Berlin, Cologne, Düsseldorf, Hamburg, Stuttgart, Leipzig, Hanover, Dresden, Bremen, and Erfurt, while airports in Bavaria, including Munich, the country’s second busiest airport, were not affected.

Meanwhile, the German Airport Association "ADV" estimated that about 1,100 flights would be canceled or delayed, affecting around 200,000 passengers.

Three rounds of labor negotiations failed to reach an agreement on wages for about 25,000 security workers, while the Verdi union seeks an increase of 2.80 euros per hour for all employees and calls for bonuses for overtime work starting from the first extra hour.