In addition, some 35 others severely injured in the blasts, according to Belgian broadcaster VRT.
Meanwhile, another explosion struck at Brussels Metro Station close to EU institutions, killing at least 10 people, local television channel VTM reported.
The attacks come four days after Salah Abdeslam, the main suspect in the Paris attacks, was captured in Brussels.
The Belgian government has confirmed 23 people have been killed so far in both explosions, however the death toll could be increase later.
The cause of the explosions is yet to be determined.
All metro lines were shut down after the attacks. Some witnesses at the Maelbeek said people with blood on their faces were seen at the scene.
Ian McCafferty, a witness at the station, said the blast happened during busy rush hour traffic.
“People started running when they saw smoke coming,” he said. “The point of these attacks is to make you live in fear but I refuse to.”
Brussels University and museums were also evacuated in the wake of the blasts.
Hundreds of people were evacuated onto the tarmac at the Zaventem Airport following the explosions.
Belgium’s interior minister, Jan Jambon, said on Monday the country was aware of the risk of a possible revenge attack following the capture of 26-year-old Abdeslam.
More details to be updated…