Two suicide bombers who set off explosions at Brussels airport and a central metro station on Tuesday have been identified as brothers Khalid and Brahim El Bakraoui and have direct links with the Paris terror attacks last November, Belgian broadcaster RTBF reported on Wednesday.

The brothers, aged 27 and 30 respectively, were already known to police for gang-related crime but until now were not connected to the terror investigation, RTBF quoted unnamed police sources as saying.

According to the report, Brahim El Bakraoui detonated a suicide bomb at Brussels's international airport. He appeared in the centre of a video surveillance screen grab published by investigators on Tuesday evening, flanked by two other men.

His brother Khalid was responsible for the suicide bombing on a subway train at Maelbeek station an hour later.

RTBF said Khalid had rented an apartment in the Forest district of Brussels which was raided by police last week, resulting in a shootout in which a suspect was killed and several police officers injured.

According to the broadcaster, Khalid El Bakraoui also rented a property in the city of Charleroi, south of Brussels, which was used to prepare the Paris attacks.

The information if confirmed establishes a direct link between the Brussels bombings on Tuesday and the Paris terror attacks on Nov. 13 last year in which 130 people died, RTBF added.

The twin attacks on Tuesday have killed at least 34 people and injured more than 180 others.