Russia has tightened access to its seaports, with president Vladimir Putin signing a decree on Monday mandating that all vessels arriving from foreign ports must now obtain prior approval from the country’s Federal Security Service (FSB).

The executive order, which takes effect immediately, marks a significant expansion of wartime maritime controls. Until now, FSB clearance was only required for ships entering ports near Russian naval bases. Under the new rules, all ships “en route from foreign ports” will be required to secure authorisation from an official representative of the FSB in coordination with the port captain.

The Kremlin has not provided a formal rationale for the move, but the decree cites a constitutional provision governing military conditions — a likely reference to ongoing martial law statutes in regions of Russia bordering Ukraine.

The announcement comes in the wake of a string of unexplained explosions targeting tankers linked to Russian trade, some occurring thousands of kilometres from Russian shores, most recently aboard StealthGas’s ammonia tanker Eco Wizard at the Ust-Luga energy hub earlier this month. That blast—officially described as a “minor leak”—triggered the evacuation of the vessel and temporary port closure. Damage inspection revealed large holes in the hull, with metal bent inward, fuelling speculation of an external attack.

Maritime security experts and Western intelligence services have speculated that Ukraine may be escalating a covert sabotage campaign aimed at disrupting Russian oil exports. 

The Eco Wizard blast followed similar incidents in February, when the Turkish-owned Koala was rocked by three explosions at Ust-Luga, and in June when the Vilamoura, a suezmax managed by TMS Tankers, was hit after calling at Russian ports.

The Ust-Luga incidents are part of a growing list of maritime explosions involving tankers linked to Russian trade, including outside the Baltic. In recent months, explosions on the Seajewel and Seacharm (both aframaxes managed by Thenamaris) in the Mediterranean, as well as the Grace Ferrum off Libya, have raised alarms among maritime security experts, many of whom suspect the use of limpet mines.

In December 2024, the Ursa Major, a Russian general cargo ship, sank in the western Mediterranean following an underwater explosion. While official statements have often downplayed these events, local authorities and international observers increasingly view them as a coordinated campaign against Russia’s export of fossil fuels.

Last week, Russia’s state-run port operator FSUE Rosmorport announced a RUB3.16bn ($39.5m) tender to inspect the underwater sections of vessels at key Baltic Sea ports amid mounting concerns over maritime sabotage.

The string of blasts recorded in recent months will likely initiate a review of war risk premium rates for vessels calling Russian Baltic Sea ports, maritime security specialist Ambrey suggested earlier this month. Ambrey is advising shipping companies to conduct asset screening assessments for all charter-party agreements and purchases, and to carry out dynamic voyage risk assessments.