No flights will be departing Brussels Airport on Monday, the airport announced, as security personnel will be on strike.
It was previously expected that at least some flights would go ahead as scheduled, but on Sunday evening the airport announced in a tweet all departing flights would be scrapped.
Arriving flights will still land, passengers can disembark safely and continue their onward journey into the capital. But layovers could become lengthy.
The reason for the cancellations is a strike by security personnel, who are calling for higher wages and more staff.
Passengers have the right to reimbursement or new booking. The airport expects long queues on Tuesday as well.
Amsterdam Schiphol Airport also saw chaos last week, as the result of structural staff shortages in combination with the pandemic.