Belgian authorities have tightened security in the port city of Antwerp after a Frenchman drove his car at high speed through a busy shopping area, forcing pedestrians to jump out of the way.

French president Francois Hollande compared the incident to the attack in London the day before, saying the Frenchman was "trying to kill people or create a dramatic event".

The federal prosecutor's office said the car was intercepted late on Thursday morning at the port docks and police arrested a man, identified as 39-year-old Mohamed R, who has been living in France.

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.

Authorities immediately raised security in the centre of Antwerp.

Trucks were used last year in deadly attacks in Nice and Berlin, and a 4x4 was used on Wednesday in London.

The federal prosecutor's 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.

Belgian prime minister Charles Michel said: "We remain vigilant. Our security services have done excellent work."

The high-speed event happened a day after Belgium held anniversary remembrance services for the Brussels airport and subway attacks, which killed 32 people on March 22 2016.

Belgium has been living under the second highest anti-terror alarm ever since.

Soldiers in the busy shopping street were immediately involved in trying to control and stop the car, which was moving away at high speed.