Riot police intervened to try to restore order after the group confronted Muslim women in the crowds, made Nazi salutes and chanted.
The attacks at Brussels airport and on the metro killed 28 people.
A "march against fear" planned for Sunday was called off after the authorities said it would strain police resources for the investigation.
Belgian police also carried out 13 new raids and took more people in for questioning on Sunday as part of investigations into the attacks.
A man already in Belgian custody was reported to have been charged in connection with a foiled attack in the Paris region.
Separately, Dutch police announced on Sunday evening that they had detained a Frenchman, 32, in Rotterdam at the request of French authorities.
He was arrested on suspicion of preparing an attack in France.
It is the latest in a series of arrests across Europe that police say are linked to planned or actual attacks.
More about:
-1780923278.jpg&h=190&w=280&zc=1&q=100)
