The main square has been evacuated
Belgian troops patrolling a major train station in Brussels have "neutralised" a person following an explosion.
Police say they are unable to confirm media reports that the suspect was wearing an explosive belt and had wires coming out of their clothes.
The incident has taken place at Brussels Central - one of the country's busiest stations - and officials say the situation is now under control.
A police spokesman said: "There was an explosion around a person. That person was neutralised by the soldiers that were on the scene."
It is not clear whether the person who was shot is still alive - but prosecutors in Brussels say no civilians appear to have been injured or killed in the explosion.
Nicolas Van Herrewegen, an employee at Brussels Central station, told reporters that the suspect had cried "allahu akbar" and blew up a trolley.
Pictures from the scene show a fire had broken out inside the station building.
A spokesman for Belgium's railway operator said a crowd in the station panicked and "ran for the tracks" after the incident.
Pierre Meys, a fire service spokesman, told RTL that some kind of explosion has happened in the station, but it is unclear what caused the blast.
Witnesses at the station have told Belgian media that they heard two loud explosions in quick succession.
Brussels Central has been evacuated and searched, with rail services from the station suspended. Grand Place, a major tourist site which lies about 200m (656ft) away, has also been evacuated.
Two other train stations in the capital, Brussels North and Brussels South, have also been cleared in what is believed to be a precautionary measure.
Belgium has been on high alert since suicide bombers killed 32 people on the Brussels subway and at an airport on 22 March 2016.
Soldiers have been stationed at railway stations, government buildings and EU institutions since.
People in the area are being pushed away from the scene, and police on Twitter have urged the public to follow instructions given by the authorities.
The incident began at about 9pm local time (8pm UK time) on Tuesday evening.
Belgium's Prime Minister Charles Michel is "following the situation very closely from the crisis centre," according to his spokesman Frederic Cauderlier.