Inmates rioted at a prison in central Russia and set several buildings on fire, injuring about three dozen prisoners and guards, officials said Wednesday.
The Interfax news agency reported that one inmate died, but that could not immediately be confirmed.
Several wooden buildings were set on fire during the unrest, which started Tuesday night at the high-security prison near the city of Samara.
Samara regional prosecutors said in a statement Wednesday that 34 inmates and guards were injured in the fight and the fires, which burned down an administrative building.
Interfax said 29 of the injured were inmates and that one was hospitalized with critical burn injuries. The news agency quoted investigators as saying they later recovered the body of an inmate who had been burned in the fires, but the prosecutors could not be reached to confirm that.
It was unclear what caused the fighting.
Interfax said the prison holds around 2,000 inmates and that many are serving sentences for drug dealing. Russia's harsh prisons, relics of the Soviet gulag system, are notoriously draconian, with inmates often kept in cruel conditions.
The passage of US warships into the Black Sea is accompanied by aggressive rhetoric, whereas Moscow does not understand Washington's goals in Ukraine