LONDON – Berlin’s both airports, Tegel (TXL) and Schönefeld (SXF), suffered some heavy flight disruptions due to a prolonged Security Staff strike.

The staff on strike are part of the Verdi union, which has called on all workers to walk out on January 7 from 5 am to 8:45 am—the busiest time of day at both airports.

Both TXL and SXF have warned its passengers of severe disruptions throughout the day. Even though the strike lasted only four hours, it had a significant impact on incoming and departing flights.

“Strike ended. There will be still severe disruption in air traffic. Enquire about the current status of your flight with your airline before traveling to the airport,” published the airline during today’s afternoon.

Approximately 60 Flights at Tegel and 20 Flights at Schönefeld have been disruped because of the strikes.

According to German News Agency DPA, Ryanair, Lufthansa, Easyjet, Eurowings, Wizzair and Aeroflot—Berlin’s biggest airlines—have all canceled flights before the strikes to try and minimize disruption.

This was the first major strike of the year in Germany. The union has stated that the Federal Association of Aviation Security Companies (BDLS), “provoked” the strikes by only offering a pay increase of 2% over the next two years to 23,000 workers across Germany before Christmas.

Currently, Security workers are paid €17.12 per hour at both of the Berlin Airports. The union wants to see the hourly pay for all security workers rise to €20.

This new proposed wage would see some security staff with a pay rise of 30%. The next round of talks will take place on the 23rd January 2019.

The strikes in Berlin are a warning to BDLS. Verdi represents 23,000 security workers across all German Airports, if the talks break down, the disruptions on air travel for the foreseeable future are likely to increase.