More than a dozen schoolchildren and at least one teacher were injured in a reported knife attack in the Russian city of Perm.
Initial reports had said that two masked men had entered the school building early Monday.
Follow-up reports said that a fight had occurred between two students wielding knives at the school, leading to the injuries of several bystanders.
The regional investigative committee has opened a criminal case into attempted murder, according to an online statement published Monday.
A teacher and one 16-year-old student were hospitalized with severe neck injuries, according to the website of the regional health ministry. Fifteen people in total were reportedly wounded in the incident, the state-run TASS news agency reported, citing the city administration's press office.
The two suspects have since been detained, a source in the emergency services told the state-run RIA Novosti news agency.