Security staff at Berlin's two airports are staging a strike that is causing disruption to flights.
The ver.di union called on staff at the German capital's Tegel and Schoenefeld airports to walk off the job from 5 to 8:45 a.m. (0400 to 0745 GMT) Monday.
German news agency dpa reported that airlines including Lufthansa, Easyjet, Ryanair and Aeroflot canceled flights ahead of the walkout. Several flights were significantly delayed.
Ver.di has said employers "provoked" the strike by offering a pay increase of 2 percent over two years.
The union wants hourly pay for all workers conducting security checks to rise to 20 euros ($22.81). Employer association BDLS says this could amount to a 30 percent increase in some cases.
The next round of talks is due on Jan. 23.