Brussels atrocities: Who were the bombers?

Four people are known to have been involved in the Islamic State bombings in Brussels on Tuesday. Two brothers, the Bakraouis, and Najim Laachraoui have been named, while the identity of the fourth bomber is unknown.

The IS bombers were known to Belgian police and had history with organised crime. Laachraoui was reported to have been a key recruiter for IS in Belgium, while the Bakraouis had links with the IS cell which attacked Paris last November.

Two suicide bombs tore through Brussels' airport Zaventem, killing 14 people and injuring scores, while 20 were killed and many more injured as a bomb struck a metro train at Maalbeck station.

Here is what has been reported of the known attackers' backgrounds.

Ibrahim and Khalid el-Bakraoui

Belgian state broadcaster RTBF reported that Ibrahim el-Bakraoui, 30, is suspected of carrying out a suicide attack at the airport. He is centre in the picture below.

Khalid el-Bakraoui, 27, was identified on Wednesday by prosecutors as having carried out the attack at the Maalbeek metro station.

The brothers were Belgian nationals from Brussels and were known for their connections to local organised crime. 

They were among those wanted by Belgian police after raids last week which caught prime Paris suspect attacker Salah Abdeslam.

One of the brothers rented the flat in the Brussels suburb of Forest where Abdeslam was caught. 

One is also known to have rented a hideout in Charleroi used by Paris attackers Abdelhamid Abaaoud, the cell's ringleader, and Bilal Hadfi, one of the Stade de France suicide bombers.

A Bakraoui brother is also believed to have provided ammunition and weapons for the Paris attacks.

Najim Laachraoui

Identified as one of the three men captured on Zaventem airport CCTV footage, and reportedly seen fleeing the airport soon after the explosions.

Reports of his arrest in Brussels on Wednesday were unfounded.

The 24-year-old grew up in the Brussels area of Schaerbeek, was reported by Belgian media to be well-known to police. His nationality has not been reported.

Laachraoui is believed to have travelled to Syria in 2013 and was thought to have been a key recruiter of Brussels youths.

An international arrest warrant was issued against him in 2014, but he reportedly travelled to Hungary in September with Paris attacks prime suspect Salah Abdeslam.

Paris investigators have since December been searching for a man called Soufiane Kayal, which it has been reported was an alias being used by Laachraoui.

Laachraoui's DNA was found in two locations used by Paris attackers and also on explosive material.

The fourth bomber

The identity of the fourth bomber has not been confirmed, but he is believed to be one of the three men caught on CCTV footage at the airport.

Belgian prosecutor Frederic Van Leeuw said on Wednesday that the man in black on the left of the footage had not been identified.