Two Swedish nationals were shot dead in Brussels late Monday by a suspect who remains at large, in an attack the Belgian prime minister described as "terrorism".
The gunman, wearing a fluorescent orange jacket, fled on a scooter and Belgium subsequently raised its terror alert to four -- the highest -- for the Brussels region, and level three nationally.
Belgian premier Alexander De Croo said the shooting had targeted Swedish citizens.
"I have just offered my sincere condolences to the Swedish PM following tonight's harrowing attack on Swedish citizens in Brussels," De Croo said on X, formerly known as Twitter.
"Our thoughts are with the families and friends who lost their loved ones. As close partners the fight against terrorism is a joint one."
Several Belgian media outlets said the two individuals killed were wearing football shirts belonging to the Swedish national team ahead of a game between Sweden and Belgium.
The Group F European qualifier match between the two countries was suspended at half-time "due to incidents," the Belgian side posted on social media accounts.
Journalists in the Roi Baudouin stadium in Brussels said fans were being kept in the ground, and the UEFA website said the match had been halted at one goal apiece.
Belgian media reported that Swedish players did not want to continue the game after the attack.
A video of a man speaking Arabic and claiming responsibility for the shooting was circulating on social media, a source close to the case said.
The federal prosecutor in charge of terrorism cases launched an investigation.
The shooting took place in the capital's northern districts. Police had been alerted to the incident after 7 pm local time (1700 GMT).
Police cordoned off the area where the shooting occurred, AFP journalists said.
In a video shared online by Flemish newspaper Het Laatste Nieuws, the shooter is seen with an automatic weapon on his shoulder, fleeing on a scooter.
Four gunshots can be heard in the video.
'Despicable'
De Croo said in an earlier post on X that he was "closely following the situation" with the Belgian justice and interior ministers at the national crisis centre.
Several metro stations in Brussels were also closed, Belgium's RTBF reported.
The European Commission president was quick to condemn the attack and offer support.
"Tonight, my thoughts are with the families of the two victims of the despicable attack in Brussels," Ursula von der Leyen said on X, formerly known as Twitter.
"I extend my heartfelt support to the Belgian police, so they swiftly apprehend the suspect. Together, we stand united against terror."
Brussels is home to EU offices including the commission, the European Council, which represents member states, and the European Parliament.
The French President Emmanuel Macron said Europe was "shaken" by an "Islamist" attack in Brussels,while the French interior minister had earlier given instructions to strengthen border controls with Belgium.
Belgium, alongside France, had already been the target of an attack claimed by Islamic State group extremists in March 2016, at Brussels' main airport and on the metro system, which killed 32 people.
(FRANCE 24 with AP)