Summary
- Russian forces have used underground pipelines for ambushes against Ukrainian troops, with notable operations in Avdiyivka (2024), Sudzha (2025), and more recently Kupyansk.
- In the Kupyansk operation, Russian troops reportedly traveled 13 kilometers under the Oskil River using carts and scooters, though Ukrainian forces claim to have thwarted the attempt.
- Ukrainian officials have confirmed Russian pipeline offensives, but said it was hard to defend against such tactics due to the vast extent of the Soviet-era underground network.
The first time was in Avdiyivka in January 2024, when Russian troops used a partially flooded water outflow tunnel to creep into a quiet, wooded district in the Ukrainian-controlled city, helping pave the way for the city’s capture weeks later.
The second was in early March 2025 in Sudzha, in Russia’s Kursk region. Ukrainian forces, who had invaded the region seven months earlier, were surprised by another group of Russian soldiers who crept through an unused underground gas pipeline. Ukrainian forces pulled out of Kursk weeks later.
Now it appears that Russian forces have pulled off a third pipeline ambush, just north of Kupyansk, a Kharkiv region city where Ukrainian forces have been under increasing pressure.
The operation, which appears to have culminated last week, involved an unknown number of Russian soldiers using carts and electric-powered scooters to secretly move as many 13 kilometers under the Oskil River.
SEE ALSO: 'The Situation Is Critical': What The Looming Fall Of Avdiyivka Says About Ukraine's Battlefield MoodUkraine controls the western banks of the south-flowing river and has relied on it in part for its defense of Kupyansk and the Kharkiv region.
It’s unclear how successful the operation was; Ukrainian officials denied initial reports, but then appeared to downplay the consequences, saying the effort had been thwarted, the pipeline destroyed and flooded, and an unknown number of soldiers taken prisoners.
Still, open-source battlefield trackers including Deep State, which has ties to the Ukrainian military, show noticeable Russian advances north of Kupyansk, home to a key junction for rail lines that stretch west into the Kharkiv region.
As of September 17, Russian troops had purportedly advanced up to Kupyansk’s northern outskirts, and possibly into the city’s limits.
If nothing else, however, it highlights both the ingenuity, or recklessness, of Russian commanders, and growing experience in undertaking risky operations.
SEE ALSO: Kursk Ambush: Did Russia Pull Off Another Pipeline Sneak Attack On Ukrainian Troops?Excavation Under Fire
Much of the pipeline network that spreads throughout Ukraine was built in the Soviet era, and Ukrainian experts said it was likely that Russian military engineers have detailed maps and schematics of the system.
According to Deep State, which first highlighted the operation late last week, Russians units entered the local, unused pipeline network in the village of Lyman Pershiy, which is about 20 kilometers northwest of Kupyansk, on the opposite, eastern bank of the Oskil River.
Units built low-slung wheeled carts and used electric scooters to move through the pipes, an assertion backed up in part by multiple videos published on Russian-linked Telegram channels. Moving under the Oskil, at a depth up to 2 meters, units took about four days to reach Radkivka, on Kupyansk’s northern outskirts. Food caches were set up along the way as well.
“It is a pity that the experiences of Avdiyivka and Sudzha were not taken into account,” Deep State said in a commentary accompanying its findings. “But once again, we want to believe that this “pipe” will finally serve as a lesson” for Ukrainian forces.
Ukrainian military officials responded by partially confirming the subterranean operation, also claiming that only a few Russian soldiers managed to emerge from the pipeline and take up forward positions, and that most had either been killed or captured.
“The exit from the pipeline that the enemy tried to use to move personnel into Kupyansk is under the control of Ukrainian defenders. The pipeline does not lead directly into the city,” the General Staff said in a statement on September 12.
In one video that was released to a prominent Ukrainian war blogger, a man identified as a Russian prisoner of war said officers sent soldiers into the pipeline in groups of 10; men who balked were tied up and beaten, the man said. He said he crawled, and used carts and scooters, to travel around 13 kilometers.
About 70 Russians had made it through the pipeline when they were confronted by Ukrainian troops, the soldier said. Commanders ordered the surrounded Russian troops to blow themselves up.
The video could not be independent verified.
Russian forces crossed the Oskil River easily when they invaded in 2022 but were beaten back months later in a rout that embarrassed the Kremlin. (file photo)
Yuriy Fedorenko, a unit commander with Ukraine's 429th Separate Unmanned Systems Regiment, said that Russian troops managed to poke holes in several places in the pipelines, particularly in wooded areas, which afforded them cover to emerge and scatter undetected by Ukrainian drones.
Ukrainian forces had destroyed one or more branches of the pipelines, making it impassible, Fedorenko told Donbas Realities, a program of RFE/RL’s Ukrainian Service.
"There was a strike near the Oskil River,” he said. “As a result, the pipeline is now impassable.”
Fedorenko said it was difficult to defend against the Russian pipeline attacks because of how extensive the underground network is, and how difficult it is to get tractors or backhoes to key locations, to dig up or block the pipelines.
Several Ukrainian reports said the pipeline in question near Kupyansk may have been partially blocked or destroyed in the past, but Russian sappers or soldiers managed to clear the route.