Soldiers have shot dead a man in Brussels after he charged troops with a knife in what authorities said was a terror attack.
The man twice shouted "Allahu akbar", Arabic for "God is great", as he charged the soldiers, said Esther Natus, a spokeswoman for the federal prosecutor's office.
"We do consider it a terror attack," Ms Natus said.
She did not identify the man or confirm whether he was known to police, saying only that "the suspect is dead" and one of the soldiers was slightly wounded.
Brussels mayor Philippe Close said three soldiers came under attack and one had been taken to hospital.
Federal Police spokesman Jonathan Pfunde said the attacker had been "neutralised" and Belgium's anti-terror crisis centre tweeted that the situation was "under control".
"All our support is with our soldiers," prime minister Charles Michel said via Twitter.
"Our security services remain on alert. We are following the situation closely."
Associated Press television images showed police had sealed off a main street near the Grand Place, a central square that is a popular tourist site.
Thomas da Silva Rosa, who lives near where the incident took place on Boulevard Emile Jacquemain, said he saw the attacker lying in the street in the aftermath.
"I live right in front of the station. It was already blocked by police at the scene and there was a man lying on the ground. The police said he had been shot by soldiers," said the public affairs consultant.
"He was lying on the ground, appeared dead."
Belgium has been on high alert since suicide bombers killed 32 people in attacks on March 22 2016, on Brussels' main airport and subway system.
Soldiers and extra police have been deployed at public buildings and around large gatherings for more than a year.