Finnish authorities have seized a ship carrying Russian oil in the Baltic Sea on suspicion it caused the outage of an undersea power cable connecting Finland and Estonia a day earlier, and that it also damaged or broke four internet lines.
A Finnish coastguard crew boarded the Cook Islands-registered ship, named by authorities as the Eagle S, on Thursday. The crew took command and sailed the vessel to Finnish waters, a coastguard official told a press conference.
The director of the Finnish National Bureau of Investigation, Robin Lardot, said: “From our side we are investigating grave sabotage. According to our understanding, an anchor of the vessel that is under investigation has caused the damage.”
The Finnish customs service said it had seized the vessel’s cargo and that the Eagle S was believed to belong to Russia’s so-called shadow fleet of ageing tankers that seek to evade sanctions on the sale of Russian oil.
Two fibre-optic cables owned by Finnish operator Elisa linking Finland and Estonia were broken, while a third link between the two countries owned by China’s Citic was damaged, the Finnish transport and communications agency, Traficom, said.
A fourth internet cable running between Finland and Germany and belonging to Finnish group Cinia was also believed to have been severed, the agency said.
The Finnish and the Estonian governments will hold extraordinary meetings on Thursday to assess the situation, they said in separate statements.
Baltic Sea nations are on high alert for potential acts of sabotage after a string of outages of power cables, telecom links and gas pipelines since 2022, although subsea equipment is also subject to technical malfunction and accidents.
The Finnish electricity grid operator, Fingrid, said in a statement that repairing the 106-mile (170km) Estlink 2 interconnector would take months, and that the outage raised the risk of power shortages during the winter.
The Eagle S Panamax oil tanker crossed the Estlink 2 electricity cable at 1026 GMT on Wednesday, a Reuters review of MarineTraffic ship tracking data showed, identical to the time when Fingrid said the power outage had occurred.
The ship was stationary near the Finnish coast on Thursday afternoon, with a Finnish patrol vessel stopped nearby, the data showed.
The United Arab Emirates-based Caravella LLCFZ, which according to MarineTraffic data owns the Eagle S, did not immediately respond to a request for comment.
Peninsular Maritime, which, according to MarineTraffic acts as a technical manager for the ship, declined to comment outside the company’s opening hours.
The Estonian foreign minister, Margus Tsahkna, said in a statement that damage to subsea installations in the Baltic Sea had become so frequent that it was difficult to believe this was caused merely by accident or poor seamanship.
“We must understand that damage to submarine infrastructure has become more systematic and thus must be regarded as attacks against our vital structures,” he said.
The 658-megawatt Estlink 2 outage began at midday local time on Wednesday, leaving only the 358MW Estlink 1 in operation between the two countries, Fingrid said.
Twelve western countries said on 16 December that they had agreed measures to “disrupt and deter” Russia’s shadow fleet to prevent sanctions breaches and increase the cost to Moscow of the war in Ukraine.
On Thursday, the Finnish president, Alexander Stubb, said on X: “We must be able to prevent the risks posed by ships belonging to the Russian shadow fleet.”
The Lithuanian foreign minister, Kęstutis Budrys, said the growing number of Baltic Sea incidents should serve as a stark and urgent warning to Nato and the EU to significantly enhance the protection of undersea infrastructure there.
Police in Sweden are leading an investigation into the breach last month of two Baltic Sea telecom cables, an incident the German defence minister, Boris Pistorius, has said he assumed was caused by sabotage.
Finnish and Estonian police also continue to investigate damage caused last year to the Balticconnector gas pipeline linking the two countries, as well as several telecom cables, and have said it was likely to have been caused by a ship dragging its anchor.
The Russia-Germany Nord Stream gas pipelines running along the seabed in the same waters were blown up in 2022 in a case that Germany is still investigating.