A Russian cargo ship, Ursa Major, sank in the Mediterranean Sea between Spain and Algeria following an explosion in its engine room, leaving two crew members unaccounted for, the Russian Foreign Ministry confirmed on Tuesday.

The vessel, built in 2009 and operated by Oboronlogistika—a company linked to the Russian Defence Ministry’s military construction projects—was carrying two massive port cranes and parts for new icebreakers. It was en route from Saint Petersburg to Vladivostok when the explosion occurred.

Out of the 16 crew members on board, 14 were rescued and taken to Spain, while the search for the remaining two continues. The cause of the explosion is still under investigation.

Unverified footage published by Russian outlet life.ru shows the ship listing heavily to its starboard side, with the bow submerged. The video, reportedly filmed on December 23, displays the two cranes secured to the deck.

According to LSEG ship tracking data, the ship, formerly named Sparta III, departed Saint Petersburg on December 11. It last transmitted a signal late Monday near Algeria and Spain. While its stated destination was Vladivostok, the vessel had previously docked at the Syrian port of Tartous.

Spanish media outlet El Español reported that the rescued crew members were evacuated to the Spanish port of Cartagena. The rescue operation involved several vessels, including one from the Spanish Navy.

Oboronlogistika and its operator SK-Yug have declined to comment on the incident. The Ursa Major was scheduled to arrive in Vladivostok on January 22.

Authorities are continuing their investigation into the explosion, with questions arising about the ship’s condition, the nature of its cargo, and the circumstances surrounding the sinking.