Timebomb fuses detonating explosions on oil tankers ‘days or weeks’ after they leave Russian ports

Timebomb fuses are detonating mines on oil tankers days or weeks after they have left Russian ports, say maritime experts.

Underwater divers, possibly using small vessels to approach the huge ships, are suspected of using limpet mines, which attach magnetically to their targets.

Some of the tankers are believed to be used by Vladimir Putin’s regime to bust sanctions imposed on Russia for his war in Ukraine.

In a new warning, maritime intelligence firm Ambrey issued a circular on “Increased Threat to Merchant Shipping Calling Russian Oil Export Hubs”.

It did not name Ukraine but said that it is “highly likely” that a state actor has targeted crude oil/oil products tankers calling at Russian ports including Novorossiysk and Ust-Luga since at least December 2024.

The attacks are suspected of being attempt to sink the ships, often some considerable time after they have left the Russian ports and hundreds, if not thousands of miles away.

“One of the vessels sank in the Mediterranean Sea, a second was damaged off the coast of Mersin, Turkey and one suffered damage in Libya,” said Ambrey.

“One vessel suffered an explosion while moored at Ust-Luga, Russia, and partially sank.”

The briefing added: “Ambrey assessed it highly likely that the geographical locations of the explosions are largely inconsequential.

“The perpetrators were likely targeting shipping for having called Russian ports, with delayed fuses.

“The attacks have likely been intended to cause total losses of vessels.”

At least four tankers and one general cargo vessel have reportedly been targeted, with most of the ships being hit with multiple explosions at the aft, near engine and machinery spaces, and underwater.

“In these recent incidents, vessels’ holes were described as ranging from 1m x 0.8m to 4m x 2m in size,” Ambrey stated.

“As they have been placed underwater, they have highly likely been placed whilst the vessels were drifting or anchored.

“These would be placed by divers, possibly with the use of swimmer delivery vehicles.”

The maritime experts added: “It is highly unlikely that naval mines would be placed whilst the vessel was alongside in port given the risks involved, but there are opportunities enroute to/from ports where vessels have slowed down sufficiently for divers to attach limpets.

“Naval mines can have mechanical or other types of delayed fuses which can be set to explode days, even weeks, later.”

The attacks will be seen as a development in the “grey warfare” increasingly being conducted by Putin’s regime and other countries.

One of the vessels targeted was the Koala which had called at Ust-Luga.

Ships suspected of being part of Russia’s “shadow fleet”, including the Eagle S, have been accused of damaging underwater cables in the Baltic Sea, and busting sanctions imposed on Putin’s regime.

A Royal Navy nuclear-powered submarine was ordered to surface last autumn close to the Yantar suspected Russian spy ship which was loitering over underwater infrastructure in UK waters, and later returned when it was monitored by HMS Somerset.

Ministers have warned that Russian vessels suspected of planning to cut undersea cables in UK waters face being raided by Royal Marine commandos.

Ukraine has carried out a number of successful sabotage operations targeting Russia.