Mass arrests, violence, inhumane conditions of detention, and mock executions — GRC presents a new report on the unlawful detention of civilians in Trostianets and the surrounding settlements of Sumy Oblast.
As of October 2025, Sumy law enforcement agencies under the supervision of the Sumy Regional Prosecutor’s Office are investigating 6,216 war crimes cases, 331 of which are resulting in murder.
Since the beginning of the invasion:
- 51 Russian servicemen were issued notices of suspicion (all in absentia), 22 of them in 2025.
- 15 indictments against 32 Russian servicemen were issued and sent to court, including 4 indictments against 10 Russian servicemen that were sent to court in 2025.
- Nine verdicts were handed down against 15 Russian servicemen (eight of which have entered into force), including two verdicts in 2025.
- In one of the criminal proceedings concerning the unlawful detention and cruel treatment of residents of the occupied Sumy region, five servicemen of the 1st Tank Army of the Russian Armed Forces were identified: Volchek M.Yu., Ilyushin P.G., Irzayev R.Kh., Mitin V.M., Ryzhkovich O.V., against whom indictments have been sent to court. The trial is ongoing.
To support the Sumy prosecutors in linking individual crimes to specific Russian units and commanders, GRC’s Mobile Justice Team (MJT) “North” — composed of Ukrainian and foreign lawyers — analysed dozens of witness and victims’ testimonies, and identified systematic patterns in the operation of detention sites established by units of the 1st Tank Army of the Russian Armed Forces in Trostianets and the surrounding settlements during the occupation.
Civilians — including local officials, veterans, police officers, and ordinary residents — were rounded up in raids or arrested on streets and checkpoints. Many were held in basements and improvised cells where they endured brutal interrogations marked by beatings, suffocation, and sexual violence. Detainees were often stripped naked in freezing conditions, blindfolded, and threatened with death or mock executions.
Outside interrogation sessions, civilians were confined in cold basements while outside temperatures dropped to –15°C, sometimes for days without food, water, heat or access to toilets or medical care.
GRC’s analysis revealed clear patterns of coordination between Russian units involved in the detentions, underscoring that such acts were not isolated but part of an organised, wider system:
- Consistent interrogation methods and torture techniques were used across different detention sites.
- Coordinated timing of arrests and detainees’ movements between sites.
- Distinct roles assigned to particular sites — such as filtration, holding, or interrogation centres.
- Repeated participation of the same units (such as the 4th battalion of the so-called “DPR” Rifle Regiment and the 423d Motor Rifle Regiment of the 4th Tank Division, subordinated to the 1st Tank Army of RFAF), suggesting a chain of command overseeing the system.
Through detailed mapping of occupation crimes and targeted legal and analytical support, GRC strengthens the capacity of the Sumy Regional Prosecutor’s Office and law enforcement agencies to build strong cases against mid- and high-ranking RFAF commanders, revealing the coordinated, large-scale and systematic nature of the atrocities committed during the occupation of Sumy Oblast.
GRC MJTs operate as part of the Atrocity Crimes Advisory Group (ACA). The ACA is a multilateral initiative established by the United Kingdom, the European Union, and the United States to support and assist Ukrainian law enforcement and prosecutors in investigating and prosecuting international crimes committed during a full-scale war.