The Skeyes air traffic controllers are unhappy with staff numbers and work pressure. An accord reached between management and unions hasn't got the support of the workforce.
In all 90 flights were cancelled at Brussels and a further ten at Charleroi. The conflict at Skeyes is far from over, though there is pressure on all parties to come up with a solution.
Delays are expected to continue all afternoon and into the evening. Many flights landed or took off with a delay and this led to scenes of chaos at the airport. A spokesman for Brussels Airport told reporters that the resumption of services was particularly difficult: "Planes are leaving one by one. The disruption will be felt all day."