Belgium's Euro 2024 qualifier at home against Sweden was abandoned at half time after two people were shot dead in Brussels prior to kickoff.
With the score at 1-1 at the interval, the game was initially suspended and fans inside the King Baudouin Stadium were told to remain inside "until security permits them to leave".
An announcement in the stadium then confirmed that the match had been abandoned after "the players decided they do not want to continue the game, because of what happened earlier today in Brussels".
UEFA then released a statement which read: "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. Further communication will be made in due course."
The prime minister of Belgium Alexandre de Croo has confirmed on social media that the victims were both Swedish, writing on X: "I have just offered my sincere condolences to @SwedishPM following tonight's harrowing attack on Swedish citizens in Brussels.
"Our thoughts are with the families and friends who lost their loved ones. As close partners the fight against terrorism is a joint one."
A post from the Swedish FA read: "Message to Swedish supporters on site in Brussels: The Belgian police want Swedish supporters to stay in the arena for security reasons. Take part in information from officials, authorities and SvFF (Swedish Football Association) staff on site.
"We will return when the Belgian authorities provide us with new information. Keep calm and take care of each other. Our thoughts go out to all the relatives of those affected in Brussels."
Initial reports from Brussels said the victims were wearing Swedish football shirts and the shooting took place before the match kicked off at 8.45pm local time.
The shooting is understood to have taken place near Boulevard d'Ypres, an area to the north of Brussels city centre and three miles from the King Baudouin Stadium.
At the time of writing, a manhunt is underway after the gunman fled the scene, and prosecutors say that they are treating the shooting as an act of terrorism.
A video on social media reported to be of the incident shows a gunman, wearing a fluorescent orange jacket and a white helmet, shooting at a man and then chasing him into a building.
Belgium's National Crisis Centre raised the terror alert in Brussels to the highest level on Monday night, and it has been moved to the second highest for the rest of Belgium.
As a result of Austria winning 1-0 against Azerbaijan earlier on Monday evening, Sweden are unable to secure a top-two finish in Group F of Euro 2024 qualifying as they sit 10 points behind second-placed Austria with three games remaining.
Viktor Gyokeres gave Sweden a 15th-minute lead against Belgium, who have already qualified, but the hosts equalised just after the half-hour mark when Romelu Lukaku scored from the penalty spot.
