Prime Minister Charles Michel took to Twitter to condemn the attack, while Interior Minister Jan Jambon called it cowardly.
Islamist bombers killed 32 people in suicide attacks at Brussels airport and a metro station in March, and many of the jihadists who carried out attacks on Paris last November in which 130 people died were based in Belgium.
Brussels, home to European Union institutions and the headquarters of NATO, and the rest of Belgium are currently on a security alert level of three out of a maximum of four, a "serious" status with a "possible and probable" threat.
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