The suspect was at large on Monday night as the threat level was raised. Prime Minister Alexander de Croo said the victims were Swedes.
Two Swedish nationals were shot dead on Monday evening in central Brussels by a single armed man, in what Prime Minister Alexander de Croo of Belgium said was an act of terrorism.
The suspect remained at large hours after the attack, Belgian police said.
“I have just offered my sincere condolences to @swedishpm following tonight’s harrowing attack on Swedish citizens in Brussels,” Mr. de Croo said on X, referring to the Swedish prime minister. “Our thoughts are with the families and friends who lost their loved ones. As close partners the fight against terrorism is a joint one.”
The victims were wearing Sweden soccer shirts, local media reported, and may have been preparing to attend a match between Sweden and Belgium at a major stadium in northern Brussels. The game was suspended after the shooting.
An unverified video of the attack circulating on social media showed a man in a white helmet and a high-visibility orange jacket pursuing and shooting at his victims who ran into a building, and then shooting them again at closer range, execution style.
Another unverified video circulating on social media, shot in selfie mode, showed a man in a high-visibility orange jacket very similar to the one worn by the shooter, speaking in Arabic and describing himself as an adherent to the Islamic State.
“So there has been a claim via social media where someone says he is the perpetrator, that he has sympathies for IS, and what is also important, he mentions the Swedish nationality of those victims,” Eric Van Der Sypt, a spokesman for the federal prosecutor’s office, told the Belgian broadcaster VTM. “For now, at the current stage of the investigation, there would be no relationship to the conflict in Gaza,” he added.
Mr. Van Der Sypt, in comments to the Belga news agency, said that a third man, a taxi driver, had been injured in the attack but was being treated in hospital and out of danger.
The threat level in Brussels was raised to level four, the highest, in the region, and France was tightening controls at its border with Belgium, France’s interior minister, Gérald Darmanin, said.
While the identity of the shooter was not released, Belgian media reported that the authorities were looking for a 45-year-old Brussels resident, and believed he’d used a scooter.
Brussels has a painful history of terror attacks as it was hit by major Islamic State terrorist bombings in 2016, which left more than 30 people dead and hundreds injured.
The Belgian capital is also home to the leading institutions for the European Union as well as the NATO headquarters.
The European Commission, which employs thousands of people, urged employees to work from home on Tuesday in view of the attack, and said it would also keep the schools and day care centers for staff’s children closed.
In a post on X, Charles Michel, the president of the European Council, said that “the heart of Europe is hit by violence.”
After midnight, some five hours after the shootings and while the shooter was still at large, fans at the Sweden-Belgium soccer game which had been suspended for hours, were being allowed to slowly leave the stadium.
Swedish fans were asked to remain and told they would be escorted by the police to a secure location, people at the game said.
Koba Ryckewaert contributed reporting from Brussels and Liam Stack from New York.