Finland boards and seizes likely Russian ‘shadow fleet’ tanker suspected of damaging power and communications cables in Baltic Sea

The Estlink 2 undersea power cable, which runs through the Baltic Sea between Estonia and Finland, malfunctioned and went offline on Wednesday afternoon, December 25. Finnish Prime Minister Petteri Orpo says the outage will not impact public access to electricity. 

Finland’s national electricity transmission grid operator is investigating the incident and has not ruled out an act of vandalism. On Thursday, spokespeople for Estonia’s national transmission system operator said that diagnostics and measurements are underway to identify the damaged area of the undersea power cable.

Reuters reported that Finnish authorities “boarded and took control of an oil tanker traveling from Russia,” believing its anchor may have damaged the power cable. Finnish officials say the tanker, registered in the Cook Islands, likely belongs to Russia’s “shadow fleet,” a group of ships used to evade sanctions on the sale of Russian oil. Officials did not find the ship’s anchor after boarding. The same vessel is suspected of damaging three communication cables, in addition to the Estlink 2, The Financial Times reported on Thursday.

Officials investigating the damaged power line are also reportedly reviewing the potential involvement of a Hong Kong-flagged container ship that came near the Estlink 2 when it went offline.

Finland and Estonia jointly own the Estlink 1 and Estlink 2 power cables. Estlink 2 has an energy transmission capacity of 658 megawatts, while Estlink 1 (which is still operating normally) has a capacity of 350 megawatts. The total length of Estlink 2 is 170 kilometers (106 miles), including 145 kilometers (90 miles) on the seabed. The Estlink 2 also malfunctioned in January 2024 and came back online only in September after lengthy repairs.