Verdi strikes airports in Düsseldorf and Cologne. Security forces at the two large airports in North Rhine-Westphalia are also due to stop work.
There will also be strikes on Thursday at Hamburg, Bremen, Hanover, Berlin, Leipzig, Dresden, Erfurt, Frankfurt/Main and Stuttgart airports. Verdi is negotiating nationwide with the Federal Association of Aviation Security Companies (BDLS) on behalf of around 25,000 industry employees.