The attack with Ukrainian-made "Sub Sea Baby" drones hit the submarine in the port of Novorossiysk where Russia has rebased many of its Black Sea naval vessels to put them out of reach of Ukrainian strikes, the Security Service of Ukraine (SBU) said.

Ukraine’s domestic security service, the SBU, said Monday that it struck a Russian submarine in the Black Sea port of Novorossiysk, causing critical damage to the vessel and effectively disabling it.

Ukraine said its naval drones damaged a Russian submarine in the Black Sea port of Novorossiysk, in a special operation it claimed was the first such attack.

Ukraine’s cheap, effective drones boost defense and exports, but extensive politicization and complex bureaucracy risk slowing production at a critical moment.

The drones are still in limited supply and are not always the ideal interception method, Ukrainian soldiers and an official told Business Insider.

Kyiv has now expressed readiness to drop its bid to join the NATO military alliance if the U.S. and other Western nations give it similar security guarantees.

The Russian submarine was allegedly carrying Kalibr cruise missiles, which Russia has used in devastating strikes on critical infrastructure and military targets across Ukraine. The SBU said the submarine was “put out of action” as a result of the blast. The FT could not independently verify the claim.

The battlefield is still dominated by aerial drones, which Syrski said are carrying out 60% of all strikes against Russian targets in the war.