A labour dispute triggered Tuesday the temporary halt of flights to and from Brussels international airport only days after it reopened in the wake of deadly jihadist bombings, officials said.
In Geneva, the International Air Transport Association, an airline trade group, condemned the strike as a "kick in the teeth for all the airline and airport staff who have worked so hard to reconnect Brussels to the world" after the March 22 attacks.
The row also disrupted flights at other airports, including at Charleroi, south of the Belgian capital, as air traffic controllers stopped work, officials said.
Staff from Belgium's air traffic control organisation Belgacontrol were protesting the terms of a labour contract, including pension terms, signed earlier Tuesday to end a dispute that erupted last month.
Controllers "said they were sick" and were not able to work, according to a statement from Belgacontrol, which said it "was looking for operational solutions."
At Brussels airport, no flights landed or took off for part of the afternoon until 1545 GMT. Some 15 flights were then scheduled to land and take off between 1545 and 1745 GMT before a new suspension occurred between 1745 and 1835, Belgacontrol said.
Some 16 new flights are scheduled between 1830 GMT and 2015 GMT, it said.
At Charleroi, arrivals were cancelled, postponed for an unspecified time, or rerouted, according to the airport's website. Meanwhile, several departing flights were delayed or cancelled, it added.
Brussels airport reopened Sunday for the first time since two Islamic State commandos blew themselves up in the departure hall on March 22 in coordinated blasts that also struck a metro station in the Belgian capital, killing a total of 32 people.
However, it will take months to repair the departure hall and full operations are not expected to resume for weeks.
Also on Tuesday police said they blocked access to Brussels airport for three hours in the late afternoon following the discovery of a "suspicious vehicle" but it was deemed later not to be a threat and traffic resumed.