The Russian news agency "TASS" reported on Tuesday that the Russian Commissioner for Human Rights described the use of torture on security detainees as unacceptable. The commissioner’s statements followed the release of videos showing the interrogation of suspects in an attack that occurred this week at a concert hall in Crocus, near Moscow, which resulted in the deaths of at least 139 people. The ISIS group claimed responsibility for the attack. A portion of one of the suspected militants' ear was cut off during questioning, and the main suspects, four in total, appeared in court in Moscow on Sunday showing visible injuries. The Kremlin declined to comment on Monday when asked if the suspects had been tortured. TASS quoted Commissioner Tatyana Moskalkova as saying, "Although the detention of criminals may be extremely important and the criminal code does not hold responsibility for harmful actions during arrest, the use of torture against detainees and the accused is absolutely unacceptable." She added that any procedural and enforcement measures must occur in accordance with the law. The Russian constitution prohibits torture, and Russia is a signatory to the United Nations Convention Against Torture.