The riot began on Friday afternoon in the number 1 penal colony of Vladikavkaz, capital of the Russian republic of North Ossetia, in the Caucasus.
According to the local branch of the Investigation Committee, at least 200 detainees took part in "massive disturbances accompanied by violence and destruction of property".
"The special forces arrived on the spot took the necessary measures to restore order," added the investigators in a statement, affirming that the incident did not claim any victims.
An investigation for "organization of massive unrest" has been opened.
This incident comes after the dismissal in early October of several prison officials following the broadcast of videos showing rape and torture of detainees in a prison-hospital in Saratov, central Russia.
On Friday, the Interfax agency quoted sources within the prison service as saying that the riot broke out after two inmates refused to obey the guards and "provoked other prisoners".
But according to the specialized NGO Gulagu.net, which has sources within Russia's vast system of penal colonies, the riot took place after guards began to beat detainees with their batons.
"To stop the violence, the prisoners cut their veins," Gulagu.net told Telegram.
Bringing the attention of investigators to prison abuse
Vladimir Ossetchkine, who heads the organization, told AFP that this kind of gesture helps to draw the attention of investigators to abuses in prisons.
He said he received a call from a detainee, who explained what happened in Vladikavkaz and shared a photograph of a prisoner with traces of violence on his back.
" It's usual.
Prison officials don't start filming until after the riot has started and only share with investigators what the inmates did, not what they themselves did, ”he said.
The case is reminiscent of similar unrest in April in Angarsk Prison Colony No. 15, in Siberia, which prisoners and human rights activists say was caused by the beating of a detainee by a guard.
The Russian prison system, inherited from the Soviet Gulag, is very regularly marred by torture scandals, committed by guards or other detainees at their orders.
