Ukraine claims first underwater drone strike on Russian submarine in Black Sea

Ukrainian underwater drones struck a Russian submarine for the first time on Monday, causing critical damage to the vessel, according to Ukraine's domestic intelligence agency.

The attack targeted a Kilo-class submarine docked in the Russian Black Sea port near Novorossiysk. At the time of the strike, the vessel carried four launchers for Kalibr cruise missiles, which Russia regularly uses to attack targets across Ukraine, the agency said. The operation marked the first publicly acknowledged use of the new class of Ukrainian underwater weapons.

The drones, designated Sub Sea Baby and operated by Ukraine's Security Service, struck the Project 636.3 Varshavyanka-class submarine. The explosion resulted in critical damage, rendering the submarine effectively out of service, according to Ukraine's Security Service statement. The operation was conducted jointly by the Security Service's 13th Main Directorate of Military Counterintelligence and the Ukrainian Navy.

Kilo-class vessels are not nuclear-powered and do not carry nuclear-armed ballistic missiles. The submarines are known as "Black Holes" due to their hulls' ability to absorb sound and remain largely undetectable by sonar.

Ukraine's Security Service noted that a Varshavyanka-class submarine costs approximately $400 million. Given current international sanctions, building a similar submarine could now cost up to $500 million, the agency stated.

The timing of the strike coincided with President Volodymyr Zelensky's meetings in Berlin with U.S. negotiators and European leaders to discuss peace proposals. The Russian government made no immediate comment on Ukraine's claim regarding the submarine strike.