Strikes will ground more than 1,100 flights on Thursday at some of Germany's biggest airports, including global hub Frankfurt, in the latest wave of industrial action by transport workers, officials said.
The labour union Verdi has called for strikes by security staff at airports across Germany as it tries to raise pressure on the government in wage talks.
Almost 200,000 passengers will be affected by the flight cancellations or delays, the German airports association ADV said on Wednesday.
In Frankfurt, security checkpoints at the transit area will remain closed, airport operator Fraport said in a statement, adding that "it is therefore not possible to board flights".
All passengers who had planned to start their journey in Frankfurt should not come to the airport, Fraport said.
A spokesperson for Berlin Brandenburg's airport said all departures would be cancelled on Thursday but that flights would go back to normal on Friday at the start of the winter holidays in Germany's capital.
The airports of Hamburg, Stuttgart and Hanover said they would take similar measures.
Reporting by Nette Nรถstlinger and Klaus Lauer; editing by Matthias Williams and Kylie MacLellan