Several German airports are witnessing the cancellation of many flights due to strikes by airport staff. No regular departures will be possible on Monday.
The trade union Verdi said that the capital's airport Berlin-Brandenburg BER and the northern German airports of Hamburg, Hanover, Bremen will be subject to a full-day strike. This is also likely to have an impact on other airports, according to German news agency (dpa).
The union has called on security staff and other employees to take industrial action.
The airports have advised travellers to contact their airline for flight status information.
In Hamburg, the industrial action was to begin on Sunday at the start of the night shift at around 10 pm (2100 GMT).
About 2,000 workers are called to industrial action there, according to union sources.
At the airports in Hanover and Bremen, the strike has been announced for 24 hours starting at midnight.
At Berlin's airport, the strike is scheduled to last all day until midnight. Around 200 departures have been cancelled.
According to the airport, about 27,000 passengers are affected by the strike.