Brussels Central Station has been evacuated after an explosion, with Belgian police saying the situation is under control.
A person wearing an explosive belt was "neutralised" inside the station, reports say.
The city's main square, the Grand Place, was also evacuated.
In March 2016, 32 people died in attacks on Brussels airport and the metro system which were claimed by the Islamic State (IS) group.
Soldiers guarding the station neutralised one person inside the station after a small explosion and there are no other casualties, Reuters news agency reports.
Brussels Central Station is one of three main terminals in the city.