A massive unannounced strike is planned at the largest airports in Germany, including Frankfurt, Munich and Berlin, on Monday. 

The strike could affect 3,400 departures and over 500,000 air travelers. 

Norwegian has canceled flights to and from Berlin, Hamburg and Düsseldorf, affecting 1,000 travelers. 

– If it is extended, we will see what happens then. We have not received any further information, says the Nordic airline's communications manager Charlotte Holmbergh to Aftonbladet.

SAS has canceled departures to Germany on Sunday and a flight from Arlanda to Berlin on Monday. 

”"Passengers who are affected tomorrow will be automatically rebooked," says Irena Busic at the company's press office to Aftonbladet.

Source: Aftonbladet.se