Belgian troops shot a "terrorist" bomber in Brussels Central Station on Tuesday in an incident being treated as a terror attack by federal prosecutors.
There were no other casualties and the situation was brought under control after people were evacuated, officials said.
Federal prosecutor Eric Van Der Sypt told reporters some three hours after the incident that a small blast was being treated as a "terrorist attack." He said it was still unclear if the man was dead and his identity was still unknown. The suspect was still inside the station, he added.
He declined to comment on witness accounts that he had shouted Islamist slogans, including "Allahu Akbar" - God is greater, in Arabic - before detonating a device on a luggage trolley in an underground concourse of the rail station.
Police had quickly evacuated the station and surrounding areas of historic downtown Brussels after the incident around 8:30 P.M. local time. The streets had been busy with tourists and locals enjoying a hot evening but were soon largely deserted and calm. Rail traffic was largely suspended.
Nicolas Van Herrewegen, a station employee, told public broadcaster RTBF that he saw a man shouting in a lower level of the 1930s station, which serves lines running under the city center. He then appeared to yell "Allahu Akbar" in Arabic and to detonate something on a luggage trolley. People standing within three meters of the trolley were unhurt, Herrewegen said.
As Belgian Prime Minister Charles Michel consulted with his security advisers, the national alert level was maintained at its second highest level.
The Belgian capital, home to the headquarters of NATO and the European Union, has been on high alert since a Brussels-based ISIS cell launched an attack that killed 130 people in Paris in November 2015. Associates of those attackers, four months later, killed 32 people in their home city, including with bombs loaded on trolleys at Brussels Airport.
Combat troops have been a fixture at transport hubs and in the main public areas since the Paris attacks. A series of further attacks in neighboring France and Germany in the past year, as well as recent bloodshed in London and Manchester, have added to anxiety.
Stationmaster Jean-Michel Michel was quoted by DH newspaper saying: "We heard the explosion. My colleague thought it was a bomb. The explosion was on the mezzanine level. The man went down to platforms 3 and 4. He said 'Allahu Akbar'... I would put him at about 35 years old."
Prosecutor Van Der Sypt said: "At about 8.30 P.M. there was an explosion in the Central Station, relatively small in size.
"The suspected perpetrator was neutralized by the soldiers present. We cannot confirm if the man is still alive or dead. There were no further victims. We consider this a terrorist attack."