The Estonian Navy will protect an undersea power cable after a major link was damaged

Nato said it would boost its military presence in the Baltic Sea, and Estonia sent a patrol vessel to protect its Estlink1 submarine power cable, after Russia was accused of destroying its main power link in the Gulf of Finland.

A ship called Eagle S is suspected of destroying the Estlink 2 cable and Finnish security personnel boarded the oil tanker and steered it into Finnish waters.

The EU said the Eagle S was part of “Russia's naval fleet” and that the submarine cable failure was “the latest in a series of alleged attacks on critical infrastructure”.

Estonia's Defense Minister, Hanno Pevkur, said the Raju had sailed early Friday morning and believed Finland would join the effort to secure the remaining cable.

He told Estonian public radio that Raju's job “is to make sure that nothing happens there and that our critical connection with Finland remains active”.

Nato Secretary General Mark Rutte said on social media that he spoke with the president of Finland, Alexander Stubb, adding that. NATO will increase its presence in the Baltic.

Finland and Estonia are both NATO members and Estonian Prime Minister Kristen Michal told public TV that, if necessary, they would invoke Article 4 of the NATO Treaty, which includes consultation if any member state feels threatened.

“Our desire would be to get Nato reinforcements with ships to be a deterrent,” he was quoted as saying by the BNS news agency.

Estonia's electricity was dramatically cut after its 170km (105-mile) Estlink 2 cable was shut down.

In its first assessment on Thursday, Finnish company Fingrid said maintenance of the line could continue until the end of July 2025.

The damage to Estlink 2 is the third incident in just over a month in the Baltic Sea.

Last month, two data cables were separated: the Arelion cable between the Swedish island of Gotland and Lithuania on November 17, then the C-Lion 1 cable between the Finnish capital, Helsinki, and the German port of Rostock was damaged.

A Chinese vessel, the Yi Peng 3, is accused of dragging anchor over the cables in a separate act of sabotage against Russia.

In October 2023, another Chinese ship exploded an undersea gas pipeline between Finland and Estonia.

The Yi Peng 3 and the Eagle S are both suspected of being part of the so-called shadow oil tankers used by Russia to evade Western sanctions imposed since the all-out invasion of Ukraine.

The EU said it was working on measures including sanctions to target “shadow Russian vessels, which pose a security and environmental threat”.

After several weeks in the Kattegat strait between Sweden and Denmark, the Chinese tanker was finally boarded by the authorities of Sweden, Denmark, Germany and Finland, but then left last week.

In contrast, Finnish authorities said they boarded the Cook Islands-registered Eagle S early Thursday and escorted it to the Finnish coast near Porkkala, across the Gulf of Finland from Tallinn.

“Our patrol vessel went to the area and was able to see that the ship's anchor was missing,” Markku Hassinen, deputy head of the Finnish Border Guard, told a press conference.

Estonia's prime minister wants to reassure Estonians on Thursday that they will continue to have secure electricity.

The two main electricity companies, Elering and Eesti Energia, have different power plants and auxiliary power plants, he told reporters.

However, he added that it was impossible to protect every square inch of the sea all the time.