Two loud explosions were heard in Brussel's Zaventem airport on Tuesday.
The passengers were seen evacuating from the airport in Belgian capital after smoke was seen rising from the terminal building.
The blasts come days after the capture of prime Paris attacks suspect Salah Abdeslam in Brussels.
The airport is being evacuated and has been closed to flights, as per reports. Rail transport to the facility has also been halted.
The cause of the blasts is not known.
Further details are awaited.