Interior Ministry official Peter Mertens said that it was not immediately clear what motivated the attack in Liege city, but said it did not involve terrorism. He said the assailant died, but did not say how that had happened. The daily La Meuse newspaper said the unidentified attacker killed himself.
Earlier media reports had said as many as three men had launched the midday attack, which left blood splattered across the cobblestone streets of a central square in Liege where people were doing Christmas shopping.
Footage from the scene showed people, including a large group of children, fleeing down the streets of the city center while some still carrying shopping bags. Ambulances and police vehicles descended on the area in eastern Belgium.