Ukrainian news agency UNIAN reported that Ukrainian forces in Kupyansk, Kharkov region, placed barbed wire inside a pipeline. According to their version, Russian troops have been using this passage to enter the city.

The discussion over underground and concealed routes intensified after Russia’s «Potok» operation in Kursk region. On August 8, the Commander-in-Chief of the Ukrainian Armed Forces, Alexander Syrsky, admitted that the military underestimated the boldness of Russian maneuvers. He acknowledged that this miscalculation allowed Russian units to move in from the rear through a pipeline.

On September 3, Russia’s Ministry of Defense released footage claiming that Russian forces control nearly half of Kupyansk’s territory.