Another Russian Oil Tanker Explodes—Already the Fourth This Year

A Greek-managed oil tanker carrying nearly one million barrels of crude oil exploded off the coast of Libya on June 27, marking the fourth unexplained blast this year involving vessels that had previously docked in Russian ports.

The tanker, Vilamoura, suffered a severe explosion in its engine room as it transited international waters near Libya. No casualties were reported among the crew, but the vessel began taking on water and is now being towed to Greece for damage assessment and investigation.

What makes the incident notable is Vilamoura’s recent port history. In April, the ship docked at Russia’s Ust-Luga terminal, and in May it visited the Caspian Pipeline Consortium near Novorossiysk—two of Russia’s major oil export points. Analysts believe these Russian links may not be incidental, as Vilamoura is now the fourth vessel in 2025 to suffer a mysterious explosion following port calls in Russia.

The three previous incidents include:

• Seajewel, a Maltese-flagged tanker, which was rocked by an underwater explosion near Savona, Italy in February. Italian authorities launched a terrorism probe after damage was found near the hull.
• Seacharm, another tanker, sustained hull damage from an apparent blast in the Mediterranean shortly after docking in Russia.
• Grace Ferrum, which experienced a similar unexplained incident earlier this year under similar circumstances.

All four tankers had either recently carried Russian oil or visited Russian ports. Maritime security firm Vanguard Tech notes that the pattern is “no longer coincidental” and has advised vessel operators to conduct underwater inspections on tankers returning from Russian terminals.

Russia, too, appears concerned. Its port authorities recently ordered diver inspections of tankers docked at key oil terminals, suggesting fears of sabotage or covert attacks. Though no actor has claimed responsibility, analysts believe these incidents may represent a growing shadow conflict targeting Russia’s oil export infrastructure and those connected to it.

The explosions come at a time of heightened geopolitical tension, with Russia facing a tightening regime of Western sanctions and growing pressure over its war in Ukraine. As Moscow leans on a loosely regulated “shadow fleet” to keep crude exports flowing, risks for operators—whether from environmental hazards or military-grade sabotage—appear to be rising.

Investigators in Greece will now inspect Vilamoura for signs of foul play. Meanwhile, shipowners and insurers across the industry are watching closely, as the world’s energy arteries grow ever more entangled with geopolitical warfare.