The prisoners include troops from Russia’s 225th Assault Brigade, as well as FSB border guards.
One captured Russian identified himself as 22-year-old Danil Kolesnikov from the Belgorod region.
In a video clip of his interrogation, the soldier said he served in the 488th regiment on the border in the Kursk-Sudzha area.
He was captured early on after Ukrainian troops crossed into Russia on Tuesday.
The soldier told his captors that the regiment’s commanders had abandoned them and that “they will die, they will die”.
Another video shows around 40 Russians being loaded onto trucks, after which they were taken to Ukraine.
Some reports claim that as many as 300 Russian servicemen had been detained by Ukraine’s army.
The Institute for the Study of War says that Ukraine’s army has managed to advance to positions along the 38K-030 route about ten kilometres from the international border.
Their analysts said that geolocated images confirmed that their soldiers had penetrated at least two Russian defensive lines and a stronghold.
A Russian insider source claimed that Ukrainian forces have seized 45 square kilometres of territory within the Kursk region since they launched the operation on August 6.
He also reported that Ukrainian forces fought for and seized the Sudzha checkpoint and the Sudzha gas distribution station.
Other Russian sources reported that Ukrainian forces have captured 11 settlements, including Nikolaevo-Daryino, Darino, and Sverdlikovo, and are operating within Lyubimovka.