A one-day strike by workers at 13 German airports, including the Frankfurt and Munich hubs and all the country’s other main destinations, caused the cancelation of most flights on Monday.

A one-day strike across Germany disrupted flights at Frankfurt airport, with delays possibly extending into Tuesday, operator Fraport said. Around 1,200 departures and arrivals were planned Monday at the airport and more than 1,000 have been cancelled, a spokesman said, adding that delays and further cancellations on Tuesday were possible.