According to the Nieuwsblad newspaper, the offender attacked bystanders with a stick.
"Two of those injured are in serious condition", the public prosecutor of West Flanders Province said, as quoted by the newspaper.
The attacker was detained by the police, he is a native of Ghana living in Belgium legally. The victims also turned out to be 'of foreign origin', but their citizenship was not specified.
The attack is now being investigated. According to preliminary information, the attacker has a mental disorder.
In 2016, the nation was rocked by two bombings at Brussels Airport and one at the centre of the Belgian capital, with a total of 32 people having lost their lives and dozens of others injured.