Belgian authorities on Thursday tightened security in the port of Antwerp after a Frenchman drove his car at high speed through a busy shopping area, forcing pedestrians to jump out of the way.
The federal prosecutor's office said the car was intercepted late Thursday morning at the port docks and a man, identified as 39-year-old Mohamed R and living in France, was arrested. Authorities then raised security in the centre of town.
In the car, authorities said they found knives, a shotgun and a gas can with an unknown liquid.
There were no immediate reports of injuries.
The incident appeared to have the hallmarks of several extremist attacks in Europe – a car in a busy area bent on mowing down pedestrians. Vehicles were used last year in attacks in Nice and Berlin, as well as on Wednesday in London, where four people died in a rampage close to Parliament.
The office said "because of these elements, and the events in London yesterday, the case is being taken on by the federal prosecutor's office," which usually deals with extremist attacks.
Prime Minister Charles Michel said "we remain vigilant. Our security services have done excellent work." He also expressed sincere condolences to British Prime Minister Theresa May.
We are working in close cooperation with our security and intelligence services, and of course, I assured my counterpart that she could count on our support and cooperation.
The events happened a day after the nation held remembrance services for the Brussels airport and subway attacks, which killed 32 people on 22 March 2016.
Belgium has been living under the second highest anti-terror alarm ever since, and soldiers in the busy shopping street were immediately involved in trying to control and stop the car, which was speeding away at high speed.