GeoConfirmed, a group of volunteers that maps Russia's war against Ukraine, published videos showing Unmanned Surface Vehicles (USVs), or ship drones, attacking ships of the Russian Black Sea Fleet in Sevastopol, a port city in Russian-occupied Crimea, on Oct. 29.
One of the published videos shows an alleged attack on a Russian Admiral Grigorovich-class frigate, and "only the Admiral Makarov matches this class for the Black Sea Feet," the investigation says. "The footage stops when the USV seems to impact on the vessel, it likely exploded," the investigation says.
Another video shows an attack on a Russian "Natya-class minesweeper." According to GeoConfirmed, 6-8 ship drones were used to attack the fleet.
Earlier on Oct. 29, Russia's Defense Ministry blamed Ukraine for sending nine drones to Sevastopol. The ministry claimed that its minesweeper and a dam suffered minor damages as a result of the strike and that its forces had downed all of the drones.
Ukraine's government hasn't commented on the alleged attack.
The strike comes two months after Russian naval headquarters in Sevastopol were targeted multiple times by drone attacks, which caused damage to the buildings on July 31 and Aug. 20.