While pipelines are normally used to transport raw materials and finished products, the raging war in Ukraine has expanded its use for an unusual purpose: transporting troops. 

Russian forces infiltrated Ukrainian defenses near the town of Sudzha by crawling through an unused gas pipeline, Ukraine’s General Staff confirmed Saturday. The unconventional tactic came as Moscow sought to regain control of areas in the Kursk region, along the Ukrainian border, that Kyiv had seized in an offensive last August.

Pro-Kremlin blogger Yuri Podolyaka, writing on Telegram, claimed Russian soldiers traversed approximately 15 kilometers (9.3 miles) inside the 1.4-meter (4.6-foot) wide pipeline, which had previously transported Russian gas to Europe. 

He alleged some troops spent several days inside the pipe before launching a surprise attack on Ukrainian units from the rear.

Sudzha, a town of about 5,000 residents, features key gas transfer and measuring stations and was once a vital conduit for Russian natural gas exports through Ukraine.

Another military blogger known as “Two Majors” reported heavy fighting in Sudzha, stating Russian forces entered the town via the gas pipeline.

Russian Telegram channels shared images purporting to show special forces operatives, equipped with gas masks, moving through what appeared to be a large pipe.

However, the claims could not be independently verified by Pipeline Technology Journal.

Ukraine’s General Staff confirmed in a Telegram post Saturday evening that Russian “sabotage and assault groups” used the pipeline in an attempt to establish a foothold outside Sudzha. The statement said Ukrainian forces “detected [the troops] in a timely manner” and responded with rocket and artillery fire.