The Euro 2024 qualifier between Belgium and Sweden was suspended at half-time after two Swedes were shot dead in Brussels earlier on Monday.
Belgium raised its terror alert to the highest level as a man in a video on social media claimed that he was the assailant and that he was from the Islamic State group.
"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 UEFA EURO 2024 qualifying match between Belgium and Sweden is abandoned," UEFA said in a statement on its website.
The Swedish players told UEFA they did not want to play the second half and the Belgians agreed, Swedish broadcaster TV6 said.
Fans remained inside the King Baudouin Stadium after the European Championship qualifier was stopped and chanted "All together! All together!"
The match was being played around 3 miles (5 kilometers) away from the shooting. The teams were tied 1-1 at halftime.
Belgium's crisis center asked citizens to avoid unnecessary travel, and the Swedish FA said in a message to the team's supporters on site that the Belgian police wanted supporters to stay in the arena for security reasons.
"Keep calm and take care of each other," the FA said. "Our thoughts go out to all the relatives of those affected in Brussels."
Belgian Prime Minister Alexander De Croo suggested the attack, which took place more than an hour before the match, was linked to "terrorism." It was not immediately clear if the shooting was linked to the international uproar over the Israel-Hamas war.
"A horrible shooting in Brussels, and the perpetrator is actively being tracked down," said Interior Minister Annelies Verlinden, adding that she was joining government talks at the National Crisis Center.
A police official, who spoke on condition of anonymity because they were not authorized to speak to reporters, said the two victims were Swedes.
"We can't play football in this situation. We and Belgium completely agree that we shouldn't play," Sweden coach Janne Andersson told Swedish website Fotbollskanalen.
Belgium have already booked their place at the finals in Germany next year, while Sweden cannot qualify.
Information from Reuters and The Associated Press was used in this story.