ISIS on Tuesday claimed responsibility for the shooting in Brussels that killed two Swedes, saying the attack targeted Sweden for its membership of a global coalition battling Islamists.
"An Islamic State fighter carried out an attack against" Swedish citizens on Monday, ISIS said in a statement issued on the its news arm Amaq.
"The attack comes in the context of operations called for by the Islamic State to target nationals of coalition countries," it added.
The gunman, of Tunisian origin living illegally in Belgium, gunned down two Swedes and injured a third on Monday evening on a street, just before the start of a Belgium-Sweden international football match.
The man, identified in reports as 45-year-old Abdesalem Lassoued, was cornered and fatally wounded early on Tuesday, when Belgian police moved in to detain him in a cafe.
The attacker had served a prison sentence in Sweden from 2012 to 2014, Swedish officials revealed on Tuesday.
In a social media post after the killings, the gunman had boasted of being inspired by ISIS.
Prime Minister Alexander De Croo on Tuesday said he believed Lassoued had targeted Swedes due to recent controversies caused by Quran burnings – some of which have taken place outside the Swedish parliament in Stockholm this year – and was also inspired by the conflict between Israel and Hamas.
The Swedish Foreign Ministry said the victims were a man in his 70s from the Stockholm region and a man in his 60s who lived abroad. A third man, in his 70s, was injured in the shooting and is in hospital.
Fans of Sweden’s football team will be advised against wearing clothing in national colours when they travel abroad, Martin Fredman, head of security for the Swedish Football Association, said on Tuesday.
“It’s the case that a perpetrator has targeted Swedish citizens so it would be reprehensible not to go with a recommendation that we should avoid [Swedish team clothing] when we are out on trips like this,” he said.
Earlier, European football's governing body Uefa announced a "moment of silence" before all of Tuesday's Euro 2024 qualifiers, in memory of the two victims.
Sweden is among dozens of nations in the Global Coalition against Daesh, formed in 2014 after the extremists seized large parts of Iraq and Syria.