BERLIN (AP) — Flights at several German airports were severely disrupted on Monday by the latest in a string of one-day strikes related to various pay disputes.

The ver.di union called workers out on “warning strikes” at Berlin, Hamburg, Hannover and Bremen airports.

Some 200 departures were canceled in Berlin, and about a third of the planned 200 arrivals were expected to be canceled, German news agency dpa reported. Hamburg airport said that all 123 planned departures during the strike were canceled and at least 50 of the 121 planned arrivals.

The walkouts by airport staff come amid difficult pay talks for employees of Germany’s federal and municipal governments.

Unions are seeking a 10.5% pay raise, while employers so far have offered an increase totaling 5% in two stages and one-time payments of 2,500 euros ($2,630) per employee — which unions have rejected as insufficient. The next round of talks is due to start March 27.

There are also negotiations ongoing nationwide over air safety workers’ pay and locally for ground service workers.