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 had been injured in the attack but was out of danger.
“I am closely following the situation, together with the ministers of Justice and Home Affairs. We are monitoring the situation and ask the people of Brussels to be vigilant,” said Mr. de Croo on X.
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.
The Belgian capital is also home to the leading institutions for the European Union as well as the NATO headquarters.
In a post on X, Charles Michel, the president of the European Council, said that “the heart of Europe is hit by violence.”
Brussels was hit by major Islamic State terrorist attacks in 2016, which left more than 30 people dead and hundreds injured.
Koba Ryckewaert contributed reporting from Brussels.