Belgian counter-terrorism police are probing the identity of a suspected suicide bomber shot dead by troops guarding a Brussels railway station after he set off explosives that failed to injure anyone.
"We consider this a terrorist attack," prosecutor Eric Van Der Sypt told reporters, declining comment on witness accounts that the man had shouted Islamist slogans before detonating what witnesses said were one or two devices in luggage.
Although no one was hurt on Tuesday night, billows of smoke pouring through Central Station and a shared awareness of Islamic State attacks in the city last year and more recently in Britain, France and elsewhere, sent evening commuters racing for cover.
Police halted rail traffic, evacuated the site and cleared streets crowded with tourists and locals enjoying a hot summer's evening in the historic city centre between the station and nearby Grand Place, Brussels' landmark Renaissance town square.
The Belgian capital, home to the headquarters of NATO and the European Union, has been on high alert since a Brussels-based Islamic State cell organised the attack that killed 130 people in Paris in November 2015.
Four months later, associates of those attackers killed 32 people in their home city.
Since then, attacks in France, but also in Germany, Sweden and, most recently, in Britain, have been carried out in the name of the Syria-based Islamist militant group by other young men, many of them locals, raising fears of more violence in a city where almost a quarter of the population of 1.2 million are Muslim.
Witnesses spoke of a man who shouted Islamist slogans, including "Allahu akbar" - God is greater - in Arabic, in an underground area of the station still busy with commuters making their way home and seemed to set off one or two small blasts.
Security experts said Tuesday's incident could have been similar to "lone-wolf" assaults carried out by radicalised individuals with limited access to weapons and training.
"Such isolated acts will continue in Brussels, in Paris and elsewhere. It's inevitable," Brussels security consultant Claude Moniquet, a former French agent, told broadcaster RTL.
With Islamic State under pressure in Syria - where Belgium has been the most fertile European recruiting ground for foreign Islamist fighters - he said attacks in Europe could increase, although many would be by "amateurs" doing little harm.
He compared Tuesday's incident to that on Paris' Champs-Elysees avenue a day earlier, when a man was killed when he rammed his car, filled with explosive and weapons, into a French police convoy. No one else was injured.