Initially, a case was opened into "violation of public order," the prosecutor's office told Interfax on Monday.
"However, more information on the incidents was received. Calls for violence and bodily harm, as well as discriminatory statements, were heard directed at the parade participants," the prosecutor's office said.
Thus, according to the police information, stones, eggs and other objects were thrown at participants of the parade. One of the participants, a Spanish citizen, sustained a concussion.

Source: www.interfax.ru