The strikes have been called by the Verdi union, Germany's second-largest, as it seeks higher pay for its members amid a surge in the cost of living.
How have the airports been affected?
The Berlin-Brandenburg airport said all passenger departures had been canceled along with some landings after security workers went out on strike until midnight (2200 GMT).
Some 240 passenger flights had been scheduled to take off, an airport spokesman said. DPA news agency reported that 70 out of 240 incoming flights had also been canceled. Some flights with no passengers, freight or empty passenger planes looking to relocate can still take off.
In the northern port city of Hamburg, workers from the private Aviation Handling Services Hamburg (AHS) have also walked off the job, announcing the action at short notice.
In a tweet, the airport urged passengers to contact the airline they were hoping to travel with or the company that organized their trip.
AHS handles check-in, boarding and lost-and-found for a number of airlines, including flag carrier Lufthansa, at Hamburg airport.
The airport said the strike would likely not affect arrivals or flights serviced by other companies.
AHS was scheduled to handle 84 of Monday's 160 departures; 31 had already been canceled by 9 a.m. (0700 GMT).
Wave of strikes
Germany has been experiencing a wave of highly disruptive strikes in various sectors in recent weeks amid high inflation.
Airports in Düsseldorf, Hamburg, Cologne-Bonn and Stuttgart were hit by strikes late last week, with Monday scheduled to be Berlin's turn.
At the weekend, German government officials and labor unions reached a pay deal for more than 2.5 million public sector workers. The agreement ended a lengthy dispute and averted disruptive all-out strikes.
However, airport employees were not included in the deal.
tj/msh (Reuters, AP, dpa)
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