MEDITERRANEAN SEA — The Russian cargo ship Ursa Major sank in the Mediterranean Sea on December 23, 2024, after an explosion in its engine room, killing two crew members. The vessel went down between Spain and Algeria while traveling from St. Petersburg to Vladivostok, and 14 other people aboard were saved by Spanish rescue craft.

A Spanish government document shows the ship's captain confessed that the vessel was carrying components for two nuclear reactors similar to those used in submarines. The Spanish parliament registered the government response document on February 23.

The ship's manifest listed 129 containers, two large cranes and two well covers. When questioned upon rescue by the Harbor Master in Cartagena, Spain, the captain revealed that the well covers were nuclear components and that the boat was not carrying nuclear fuel.

Spanish authorities were not able to search the ship to confirm the information during the rescue operation, which focused on saving the crew and searching for the two missing members. The wreck rests at a depth of 2,500 meters, making further investigation of the site difficult.

Oboronlogistika, the ship's operator, said the Ursa Major was sabotaged and that three powerful explosions damaged the boat just above the water line in what the company described as a terrorist attack. Oboronlogistika was established under Russia's defense ministry and placed under U.S. and European Union sanctions for its ties to Russia's military.

The Ursa Major was a Russian-flagged vessel. The sinking occurred as the ship was en route from St. Petersburg to Vladivostok, a route that passes through the Mediterranean. The two crew members who died were among those unaccounted for during the initial rescue effort, while the remaining 14 were recovered by Spanish rescue craft operating in the area between Spain and Algeria.