NATO magnetic mines, found on an oil tanker that came from the port of Antwerp. Russia's accusations

Several magnetic mines were detected on an oil tanker in the Russian port of Ust-Luga on the Baltic Sea, Russia's Investigative Committee said on Monday, according to Reuters.

The committee said the mines, manufactured in a NATO member country, were found by divers during an inspection of the hull of the tanker Arrhenius, which arrived from the Belgian port of Antwerp to load liquefied petroleum gas.

Russia has tightened security measures at its ports following suspected acts of sabotage aimed at undermining its energy infrastructure.

NATO did not mine any oil tankers, a NATO official said in an emailed statement.

Last year, Russia ordered divers to inspect ships in its ports after suspected attacks on four oil tankers. The Suezmax Koala tanker ran aground at Ust-Luga after an engine room explosion in February 2025.

According to LSEG vessel tracking data, the tanker Arrhenius is Liberia-flagged and managed by Maple Mariner Holding of the United Arab Emirates.

A spokeswoman for Russia's Investigative Committee, Svetlana Petrenko, said the mines were produced by a NATO country. She said the ship, which entered Ust-Luga on May 20, was to sail to the Turkish port of Samsun.

The mines have been deactivated, she said.

“Based on the initial actions of the investigation, it can already be concluded that the magnetic mines could not have been installed in the territorial waters of Russia,” Petrenko said.