Moscow (Agencies): August 13, 2025 — Russian state media and pro-Russian channels have claimed that a Project 636.3 “Varshavyanka” submarine sank a merchant vessel near the Danube delta late last month, alleging the ship was carrying Western-supplied weapons to Ukraine.
According to the Russian Ministry of Defence, the attack took place on the night of July 25–26 in the western Black Sea, along a route used for grain exports between Ukraine and the Bosphorus. The ship, reportedly flying the flag of a NATO member, was described by Moscow as “civilian-registered” but allegedly carrying a large cache of weapons and equipment.
The claimed inventory included:
– 60 M1A1 Abrams tanks
– 300 Javelin anti-tank missiles
– 150 Stinger anti-aircraft missiles
– 150 Block 1 anti-tank complexes
– 200 tons of small arms (M4 rifles, AK416 machine guns), grenade launchers, and 155mm artillery ammunition
The Russian side described the explosion as being witnessed by Romanian fishermen, who allegedly compared it to “sunshine at night.”
The submarine involved, according to Moscow, was a Project 636.3 “Varshavyanka” diesel-electric attack submarine—an improved Kilo-class platform known for its stealth. Nicknamed “Black Hole” by the US Navy, the vessel is designed for anti-ship and anti-submarine warfare in shallow waters and can carry heavyweight torpedoes, mines, and Kalibr cruise missiles. With a submerged displacement of around 4,000 tons and a range of up to 7,500 nautical miles, the 636.3 variant is equipped with advanced noise-reduction measures, making it difficult to detect during operations.
However, these claims have not been independently verified. No confirmation has been issued by NATO, Ukraine, or maritime authorities in Romania or Bulgaria. Searches of international maritime incident records and shipping databases show no reported loss of a NATO-flagged merchant vessel in the region during that period.
Romanian and Bulgarian officials have not reported any emergency at sea or search-and-rescue operations matching the description. NATO has not commented on the Russian statement, and independent maritime analysts note that such a large-scale incident would typically generate observable satellite imagery, oil spill reports, and insurance filings.
The Black Sea remains a tense and contested zone, with both Russia and Ukraine targeting shipping routes since the collapse of the UN-brokered grain deal in 2023. While incidents involving mines, missile strikes, and vessel seizures have been documented, this latest alleged attack has so far not been corroborated by publicly available evidence.