Dozens of flights to and from Amsterdam's busy Schiphol Airport have been delayed or cancelled because of a technical problem with air traffic control systems.
Schiphol said that the problem was resolved by late afternoon, but passengers could still face delays into the evening.
KLM, in a tweet, called the problem a "major disruption" and said it cancelled 25 European return flights.
Air Traffic Control the Netherlands said in a statement that its systems had been successfully restarted but added that it would take time before the system was working at full capacity again.
KLM is experiencing a major disruption at Schiphol as a result of technical failure at Air Traffic Control The Netherlands (LVNL). So far, 25 European return flights have been cancelled. At the same time, KLM is struggling with major delays resulting from— KLM Newsroom (@KLM_press) November 21, 2017