The arrests were announced by Police on Thursday, and follow investigations into the incident where two teens were seriously injured.
Despite a lack of confessions from the two main suspects, police announced on Friday at a press conference that they have decisive evidence.
The protest march being held to support the Kurds under siege in the town of Kobane in Syria was beset by violence.
In one case, a 17-year-old from Thailand was attacked by a 25-year-old Turkish citizen from Dornbirn.
In a second case, a large group of people surrounded another 17-year-old, who was badly beaten and stabbed in the chest. After viewing video and photographic evidence, police arrested a 34-year-old Austrian of Turkish origin as the principal culprit.
The two primary combatants have been charged with intentional aggravated assault, and are being held in custody. The remaining three have been charged with affray, according to the lead investigator, Norbert Schwendinger.
The arrests, in which the armed police Task Force Cobra was involved, went "smoothly" according to police. Several seized objects will be thoroughly checked as to whether they were used as the weapons.