One-day strike of workers on the 13th German airports, including hubs in Frankfurt and Munich, and all other major destinations in the country, led to the cancellation of thousands of flights.
Na airport in Frankfurt on Monday, 1.054 of the 1.116 planned take-offs and landings were cancelled.
All regular departures and arrivals at the Berlin airport have been cancelled, while the Hamburg airport has announced that there will be no departures from there, writes AP.
German media reports that more than 500.000 passengers were affected.
"Passengers should expect a significantly reduced flight schedule"
Cologne/Bonn Airport said there were no scheduled passenger services, and Munich Airport advised passengers to expect "significantly reduced flight schedules".
The strike by Ver.di, Germany's second largest union with 1,9 million members, is aimed at airports in Hamburg, Bremen, Hanover, Berlin, Dusseldorf, Dortmund, Cologne/Bonn, Leipzig/Halle, Stuttgart and Munich.
The so-called "warning strike" was announced on Friday and is a common tactic in wage negotiations in Germany. It relates to negotiations over a new contract on wages and conditions for airport security workers and a broader dispute over wages for federal and municipal government employees.
Request for a salary increase
The latter has already led to the walkout of employees at the airports in Cologne/Bonn, Dusseldorf, Hamburg and Munich. Wage talks in the dispute are due to resume on Friday, while the next round of talks for airport security workers is expected to begin on March 26.
The union is demanding an 8 percent salary increase for airport workers, or at least 350 euros per month, along with higher bonuses and additional time off. Employers have so far rejected these demands as unrealistic.
Strikes at facilities operated by the federal government and local governments are expected to continue this week.