Two of the Brussels attackers have been identified as brothers Khalid and Ibrahim el-Bakraoui, who acted as suicide bombers at Maelbeek metro station and Brussels airport respectively. The two Belgians were already being sought by police due to suspected links to the November terror attacks in Paris.
Najim Laachraoui has been tentatively identified as the second airport bomber by French and Belgian media reports, but this has not been confirmed. Reports on Tuesday that he had escaped and was later arrested proved to be wrong.
The identity of a third man seen at Zavantem airport has not yet been established. Officials said he is thought to have fled the scene after his own bomb failed to detonate. A manhunt is underway.
French newspaper Le Monde has reported that a second man, carrying a large bag, was seen on CCTV in the Brussels metro with Khalid el-Bakraoui. This is the first mention of a second attacker in the metro bombing and the Guardian is not yet able to verify this.