In a significant escalation of maritime warfare, Ukraine announced on Monday that it successfully executed an underwater drone attack, severely damaging a Russian Kilo-class submarine stationed at the port of Novorossiysk. This marks the first known incident of such an attack, showcasing Ukraine’s growing maritime capabilities.

The Ukrainian Security Service (SBU) revealed that its sophisticated “Sub Sea Baby” underwater drones targeted the Russian submarine, which was outfitted with four launchers for Kalibr cruise missiles—arsenal frequently used against Kyiv and other regions in Ukraine.

This strategic operation was a collaborative effort involving the Ukrainian Navy alongside the SBU’s 13th Main Directorate of Military Counterintelligence. Their joint action highlights Ukraine’s commitment to countering threats from the sea.

Accompanying the announcement, the SBU released a dramatic video capturing the moment of impact. The footage shows several vessels moored at the Novorossiysk naval base, located in Russia’s Krasnodar region, before a powerful explosion rocks the scene, underscoring the precision and impact of the attack.

The incident, dated December 15, 2025, by the Ukrainian Security Service, indicates a pivotal shift as the Novorossiysk base increasingly serves as a strategic haven for Russia’s naval operations. This comes amid intensified Ukrainian assaults on Sevastopol and other ports in the occupied Crimean territory, further complicating the maritime dynamics in the region.

The base has become a key refuge for Russia’s fleet as Ukraine intensifies strikes on Sevastopol and other occupied Crimean ports.

The SBU said the submarine had been forced to remain in Novorossiysk because of other Ukrainian operations, including the use of Sea Baby surface drones that drove Russia’s Black Sea Fleet out of Sevastopol Bay.

A spokesperson for Russia’s Black Sea Fleet denied the strike caused any damage, writing on Telegram that no submarines or crews were harmed.

President Vladimir Putin visits the destroyer Vice-Admiral Kulakov at the Black Sea Fleet’s naval base on Sept. 23, 2014, in Novorossiysk, Russia. (Sasha Mordovets/Getty)

“[Ukraine] once again proved that minnows can swallow sharks using innovation,” drone expert Brett Velicovich told Fox News Digital. “Underwater drones are the next evolution in drone warfare.”

The submarine strike comes as Russia continues to launch large-scale drone and missile attacks on Ukraine and as the United States works to end Russian President Vladimir Putin’s war.

A mother cries at the coffin of her son, Oleh Borovyk, a Ukrainian serviceman killed in fighting with Russian forces near Pokrovsk, during his funeral ceremony in Boiarka, Ukraine, on Dec. 3, 2025. (Evgeniy Maloletka/AP)

Ukrainian President Volodymyr Zelenskyy and his negotiating team met in Berlin on Sunday with U.S. Special Envoy Steve Witkoff and Jared Kushner, President Donald Trump’s son-in-law, to discuss security guarantees for Ukraine.

Zelenskyy also held talks with European leaders earlier in the week on a broader political framework to end the war, secure long-term protections for Ukraine and support the country’s postwar recovery.