Multiple reports describe a battlefield tactic in which Russian forces reportedly move personnel through underground infrastructure to bypass Ukrainian defensive positions. According to accounts from the northeastern Kharkiv Oblast area, a Ukrainian sergeant with the Khartiia Brigade describes Russian troops entering underground pipes and later emerging on the other side of Ukrainian lines. The reporting frames this as an effort to reduce exposure to frontline surveillance and defenses by using subterranean routes rather than approaching directly on the surface.
The same sources characterize the encounter as a rapid, high-risk “whack-a-mole” pattern involving drones and short time windows for detection and response. The implication is that once personnel appear outside the underground passages, they face immediate targeting or engagement attempts, with casualties occurring quickly. The reporting does not provide independently verifiable operational details such as confirmed numbers of tunnel crossings, timing, or the extent of underground infrastructure. Overall, the sources present the tactic as an emerging method within the ongoing conflict in and around Kharkiv Oblast, emphasizing the danger to troops once they surface.
