Frankfurt Airport will be closed to departing passengers on Thursday due to a strike by security staff, a spokesman for the operator Fraport said on Wednesday.
The operator recommends that passengers contact their airlines and said they should not travel to the airport under any circumstances.
The impact on the flight schedule remained initially unclear. So far, planes are still expected to land and passengers on incoming flights are expected to be able to change at Frankfurt.
Trade union verdi has called on ground staff at Germany's national carrier Lufthansa to strike from Wednesday evening in a current wage dispute for around 25,000 employees. On Tuesday, security staff at Frankfurt and Hamburg airport were asked to join the action on Thursday.
The workers are employed by private companies that check passengers, staff and luggage at the entrances to the security area on behalf of the Federal Police.
The strike by Lufthansa ground staff begins on Wednesday evening and is scheduled to continue until Saturday morning at 7:10 am (0610 GMT).
Passenger flights are expected to be mainly be affected on Thursday and Friday, but so far Lufthansa has not amended its schedule according to the additional strikes at Frankfurt and Hamburg airports. Even before security staff there were called on to join the action, the airline was expecting massive flight cancellations, especially at its hubs in Frankfurt and Munich.
