The shooting reportedly took place near Boulevard d'Ypres, north of the city centre and three miles from King Baudouin Stadium, where the match was taking place. The victims were two people wearing Sweden football shirts, per local Dutch-language newspaper Het Laatste.
A manhunt is underway for the gunman, and law enforcement have cordoned off the scene but are yet to make any arrests. The incident occurred before Belgium's game against Sweden in Brussels in a Euro 2024 qualifier.
Videos purporting to be of the incident circulating on social media show a gunman chasing a person into a building and gunshots are then heard. The gunman is then thought to have fled the scene wearing a fluorescent orange jacket.
"I was completely in shock and immediately started shouting," said one witness to Het Laatste.
Belgium's prime minister, Alexander De Croo, reacted to the shooting in a post on X, formerly known as Twitter.
"I have just offered my sincere condolences to the Swedish PM following tonight's harrowing attack on Swedish citizens in Brussels," he wrote.
"Our thoughts are with the families and friends who lost their loved ones. As close partners, the fight against terrorism is a joint one."
Mayor of Brussels Philippe Close also issued a statement on the current situation.
"Following the shooting in Brussels, the police have mobilised to secure the city and the surrounding areas, working with the minister of the interior," he wrote on X, formerly Twitter. "I am present at the crisis center with to ensure coordination with Michel Goovaerts."
Monday evening, Belgium's national crisis centre raised their terrorist alert to the highest level in Brussels and the second-highest across the rest of the country, which then saw the match between Belgium and Sweden abandoned at half-time.
Players reportedly refused to take the pitch for the final 45-minutes, with a PA announcement in-stadium saying "the players decided they do not want to continue the game, because of what happened earlier today in Brussels."
A UEFA spokesperson said: "Following a suspected terrorist attack in Brussels this evening, it has been decided, after consultation with the two teams and the local police authorities, that the qualifying match between Belgium and Sweden is abandoned."
All in attendance were told not to leave the stadium for security reasons.
