Russian forces pull off third subterranean ambush in Ukraine

In the ongoing conflict in Ukraine, Russian forces have reportedly executed a successful subterranean ambush near the city of Kupyansk in the Kharkiv region. This ambush, which is believed to have occurred in the weeks leading up to September 2025, marks the third instance of such tactics being employed by Russian troops. Previously, similar tactics were utilized in Avdiyivka in January 2024, where Russian soldiers infiltrated through a flooded water outflow tunnel, facilitating their advance into the city. Ukrainian defensive strategies were caught off guard during those exploitations, enabling Russian troops to capture key areas. The latest report suggests that as many as thirteen kilometers were traversed by Russian soldiers beneath the Oskil River, utilizing carts and electric scooters for stealthy movement. Furthermore, Ukrainian sources have acknowledged challenges in combating these subterranean advancements due to the extensive and complex underground pipeline networks. Russian troops were able to set up food caches along their route, indicating meticulous planning and preparation for prolonged engagements. However, Ukrainian officials claimed that they had successfully thwarted the ambush to some extent by damaging the pipelines, but open-source battlefield trackers indicate that significant territorial gains have been made by Russian forces in the region, leading to heightened tensions over control of vital transport links in the area. This operation underscores the ongoing innovation and adaptability of Russian military tactics in urban warfare, thereby escalating the challenges faced by Ukrainian forces in their defense operations. As of September 17, 2025, reports indicate that Russian troops may have advanced to the northern outskirts of Kupyansk, raising alarm regarding the potential capture of this strategically important city.