BERLIN (AP) — Security staff at three German airports is staging a strike that is causing severe disruption to flights.

The ver.di union called on staff at airports in Duesseldorf, Koeln-Bonn and Stuttgart to walk off the job all day Thursday.

German news agency dpa reported that hundreds of flights were canceled at the three airports and up to 110,000 passengers may be affected.

Other airports were also affected by the strike including Berlin where 90 flights had to be canceled at the capital's Tegel airport and another four at Schoenefeld airport.

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).