Air traffic controllers said the closure was the result of a "problem with flight plan data"
Travellers in Europe have been experiencing more flight disruption today after airspace above Belgium was temporarily shut.
It came after a technical glitch, described as a "problem with the loading of flight data information".
Some planes were grounded while others were prevented from landing.
Brussels Airport, which handles around 650 flights every day, said the issue was "an exceptional situation".
Air traffic control announced that the situation was resolved at around 6pm local time (5pm Irish time).
Problem with flight plan data is resolved. Belgian sky totally open again.— Belgocontrol_EN (@Belgocontrol_EN) July 19, 2018
However, Brussels Airport was still experiencing significant disruption this evening, with dozens of flights delayed or cancelled.
Passengers were being urged to check the status of their flight before travelling to the airport.
Other Belgian airports - including Brussels South Charleroi Airport and Antwerp International Airport - also reported delays and disruption.
This summer has seen flight disruption in Europe as a result of a range of issues, including multiple strikes and airline staffing problems.