Russia Reports Magnetic Mines Found on Tanker at Ust-Luga Port

Russian investigators said on Monday that several magnetic mines were discovered on the hull of the Liberia-flagged tanker Arrhenius during an inspection in the Baltic Sea port of Ust-Luga in Russia’s Leningrad region. The tanker had arrived from Belgium’s port of Antwerp to load liquefied petroleum gas and was scheduled to continue to the Turkish port of Samsun, according to Russia’s Investigative Committee and ship-tracking data cited in the report.

The committee said divers found the devices during a hull inspection and that the mines were manufactured in a NATO country. Russian officials said the mines had been deactivated and argued that, based on initial investigative steps, they could not have been planted in Russia’s territorial waters. A spokesperson for the committee, Svetlana Petrenko, made the claim as part of the initial findings.

The report comes amid heightened Russian security at ports following suspected sabotage incidents that Moscow says have targeted its energy infrastructure. Russia has already increased underwater inspections of ships in its ports after earlier suspected attacks on four oil tankers. In one prior incident, the Suezmax tanker Koala ran aground at Ust-Luga after an explosion in its engine room in February 2025.

NATO officials denied involvement. A NATO official said in an emailed statement that NATO has not mined any tanker, rejecting Russia’s accusation.

Ship-tracking data identified Arrhenius as being managed by Maple Mariner Holding in the United Arab Emirates. The vessel was in Ust-Luga on May 20 and was due to sail onward after loading cargo. Russian state media released video showing what it said was a mine found on the ship’s hull.

The claim is the latest in a series of allegations surrounding maritime security in the Baltic Sea and the protection of Russian port infrastructure. Moscow has repeatedly pointed to sabotage threats as it tightens port controls and expands inspections. Russia has not provided public evidence in the report to substantiate the origin of the devices beyond its assertion that they were made in a NATO country. The discovery has added to tensions over shipping security and the risk of interference with commercial vessels operating in the region.