The Brussels prosecutor's office said that "several people" were beaten up and one elderly woman also landed up in hospital after the melee outside the embassy on Thursday.
Belgian Prime Minister Charles Michel warned that the government will not tolerate violence as Turks living abroad vote on a referendum that would give Turkish President Recep Tayyip Erdogan more power.
Turkish citizens in six European countries have until April 9 to vote in the referendum. The deadline in Turkey is a week later.