Ukraine strikes Russian Kilo-class submarine docked in port

The Ukrainian military and security services pulled out another impressive feat by destroying a Russian Kilo-class submarine on Monday.

Using underwater drones, the Ukrainian forces landed hits on the Russian attack submarine while it was in the Novorossiysk port.

In a video released by the Ukrainian security services, naval drones can be seen rushing up the docked submarine without any opposition. A large blast ensues after contact is made with the Russian vessel.

The Ukrainian Security Service (SBU) claimed that the Russian submarine suffered “critical damage” as a result of the attack and was “put out of action.” However, it might be some time before a proper post-attack assessment reveals the extent of the damage. SBU identified the Russian submarine as the Kilo-class Varshavyanka, which presumably costs $400 million.

The Ukrainian forces very likely targeted the Russian submarine because of its participation in Russia’s long-range fires campaign against Ukraine. The vessel was allegedly carrying Kalibr cruise missiles, which Moscow has used in conjunction with suicide drones and air-launched ballistic and cruise missiles to target Ukraine’s critical infrastructure and energy grid.

In a massively successful raid, Ukrainian undersea drones snuck into Russia's Novorossiysk harbor and blew up a Kilo-class submarine. pic.twitter.com/JYpKvmTtUB
— OSINTtechnical (@Osinttechnical) December 15, 2025

This is the second Russian submarine likely taken out of action after the Ukrainian forces struck the Rostov-on-Don – another Kilo-class sub – twice, first on September 2023 and then on August 2024.

This is the latest Ukrainian attack using unmanned maritime systems. A few days ago, the Ukrainian forces employed Sea Baby underwater drones to strike a tanker serving in Russia’s shadow fleet. Moscow has been using ghost ships to maintain its exports and imports of oil, natural gas, and other goods, thus bypassing international sanctions.

The attack against the Russian submarine while at port reveals serious security shortcomings on the part of Moscow. Indeed, the Russian Navy seems unable to ensure the protection of its Black Sea Fleet from Ukraine’s missiles and unmanned systems.

Ukraine does not have a surface navy. Nevertheless, the Ukrainian forces have managed not only to restrict the powerful Russian Navy’s Black Sea Fleet in its ports in Crimea and Russia, but also to cause heavy casualties to it. The Black Sea Fleet has lost several warships, submarines, and support vessels sunk, destroyed, or damaged by Ukrainian missiles and drones. According to Western intelligence estimates, the Ukrainian forces have taken out of action more than 25% of the Russian Black Sea Fleet. The fleet has even lost its flagship, the Moskva guided-missile cruiser, which was sunk by Ukrainian Neptune anti-ship missiles in the opening weeks of the war.

Feature Image: Screenshot of video released by Ukraine showing the attack against the Varshavyanka submarine. (Osinttechnical via Creative Commons)

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