The prisoners who took hostages at Russian penal colony IK-9, identified themselves as fighters of the "Islamic State" group, reported Reuters, quoted by BTA.
A video released by Russian media outlet Mash shows at least two attackers, one of whom shouts that they are "Mujahideen". from "Islamic State" and that they established control over the prison in Volograd region.
The footage also shows prison officers lying motionless, one of whom has his throat cut. A fourth in uniform sits by the neck, and one of the attackers has a knife to his throat.
TASS reported that at least one employee of the penal colony was killed, but from what was published by "Mash" video it is clear that the number of victims is almost certainly higher, notes Reuters.
"During a meeting of the colony's disciplinary commission, several inmates attacked the staff," the Federal Service for the Execution of Penalties said earlier today. "At the moment, measures are being taken to release the hostages. "There are wounded", added the service.
IK-19 high-security prison is located in the city of Surovikino, Volgograd Region. According to open sources, the penal colony has the capacity to accommodate over 1,200 inmates.
Russian news sites released the names of some of the alleged attackers and identified them as citizens of Uzbekistan and Tajikistan. However, this information has not been officially confirmed.
Russia has recently seen an increase in attacks carried out by armed Islamists at a time when Russian defense and security services are heavily focused on the war in Ukraine, Reuters notes.
In June, a prison riot linked to the "Islamic State" broke out in the southern Rostov region. Hostages were also taken then, with special forces shooting dead six of the kidnappers.
Later that month, at least 20 people were killed in attacks in two cities in Russia's predominantly Muslim republic of Dagestan.
In March "Islamic State" took responsibility for the bloody attack in the concert hall "Crocus City Hall" near Moscow, where over 140 people were killed.