Jens Asbjørn Bøgen
The last attempt yielded mixed results – this time, Ukrainian troops turned it into a total blowout.
Russian assault teams have gone back to a tactic that first drew attention in 2024, when they crawled through an industrial gas main to attack Avdiivka.
Over the past week the same trick has resurfaced along the Sumy front, where Moscow’s ground offensive has stalled.
The Institute for the Study of War (ISW), citing a spokesperson for Ukraine’s 8th Airborne Corps, assessed on September 21 that Russian forces “have reverted to the practice of moving through the Urengoy-Pomary-Uzhhorod gas pipeline that connects Sumy Oblast and Sudzha, Kursk Oblast.”
ISW documented at least two such attempts since September 13, including one involving a platoon-sized group.
Sudzha is the Russian town on the other side of the border, in Kursk Oblast. The Urengoy-Pomary-Uzhhorod line was for decades the backbone of Soviet and then Russian natural gas exports to Europe.
29 killed near Mala Korchakivka
The heaviest reported ambush in the current wave came when a larger Russian group tried to push toward Mala Korchakivka, north of Sumy.
Ukrainian forces killed 29 Russian soldiers and wounded three during that assault, according to a Ukrainian brigade cited by ISW on September 15.
An earlier attempt in the same stretch was reported on September 12, when Ukraine’s 47th Separate Mechanized Brigade “Magura” and neighboring units struck about a dozen Russian assault troops emerging from the pipe, using artillery, drones, and small-arms fire.
The brigade said the passage was under constant surveillance.
ISW notes that despite the renewed pipeline use, Russian offensive operations along the northern Sumy front on September 20 and 21 produced no confirmed advances.
Not a new trick
The Urengoy-Pomary-Uzhhorod system is not the first pipeline Russian forces have used as cover.
According to the ISW assessment, similar tactics were deployed at Avdiivka in January 2024, inside Russia’s Kursk region in March 2025, and near Kupiansk in September 2025.
Ukrainian units have intercepted earlier pipeline pushes as well. On April 14, Ukraine’s 71st Separate Airmobile Brigade reported killing nearly 30 Russian soldiers who tried to move through a gas pipeline in Sumy Oblast, after the group attempted to exploit poor visibility to breach Ukrainian defenses.
