The Daily Mail reports:
Two explosions have been heard at Brussels Airport, it was claimed this morning.
Witnesses said they ‘felt the shockwaves’ of the blast while shopping in the duty free section of the airport.
Several people injured and hundreds are trapped inside the terminal after an explosion at the American Airlines desk.
This would be before the security checks, so difficult to stop or detect. Hopefully the death and injury toll is minimal (except for the perpetrators). Must be terrifying for those there.
UPDATE: Sadly not minimal. At least 34 dead and 130 injured in three explosions. 14 dead at the airport and 20 dead at a metro station.