On Monday morning, KLM had to cancel 56 flights to and from Schiphol due to the ground staff strike. Eleven European return flights were already scrapped as a precaution. Travelers flying with KLM have to take account of delays for the rest of the day.

Around five hundred KLM employees were on strike as announced between 8 a.m. and 10 a.m. The FNV had taken into account about four hundred strikers, but was short of the “overwhelming” turnout vests, says FNV campaign leader Joost van Doesburg.

The trade union wants, among other things, a wage increase of 8 percent in two years, a less flexible schedule and more people in permanent employment. If KLM does not respond to this, new actions will follow this week, says Van Doesburg. KLM did not respond to trade union proposals during the negotiations last week.

KLM handled all incoming European flights on Monday morning. The airline’s intercontinental flights were delayed by about two hours due to the work interruption.

Due to the risk of delays, Schiphol advises travelers to keep an eye on the airport’s website.