A video confessing to the double murder, in which a man speaks in Arabic, circulated on social networks on Monday evening, a source familiar with the case reported.
A spokesman for the Brussels public prosecutor’s office contacted by AFP only made it clear that an investigation had been initiated, without being able to initially comment on the motive.
The Federal Prosecutor’s Office responsible for terrorism was commissioned to investigate.
According to a video posted on the website of the Flemish newspaper Het Laatste Nieuws, the gunman, wearing a fluorescent orange jacket and riding a scooter, fled after using an automatic weapon he shouldered to fire at least four shots.
According to sources, the two victims wore the colors of Sweden when the Belgium-Sweden match, which counted towards qualifying for the Euro 2024, took place in Brussels this Monday evening.
The game was also stopped at half-time, but with the suspected shooter still on the run, spectators were asked to remain inside King Baudouin Stadium while a security perimeter was set up.
The Belgian Prime Minister condemned an “attack” aimed at Sweden.
“My heart goes out to the families of the two victims of the heinous attack in Brussels this evening,” said European Commission President Ursula von der Leyen on X (ex-Twitter). “We are united against terror,” she added.
The events took place near Place Saintelette in the northern district of the Belgian capital.
Border controls in Belgium have been strengthened.