Major General Nikoliuk to lead Donetsk OTG, replacing Tarnavskyi – media Brigadier General Oleksandr Tarnavskyi, who commanded the Donetsk Operational-Tactical Grouping, has stepped down. He will be replaced by Major General Viktor Nikoliuk, the current chief of staff, as commander of the OTG. 3 979 7 Previously in trend: Appointment of Viktor Nikoliuk Resignation of Tarnavskyi