'Grave sabotage' | Nato to 'enhance military presence' in Baltic Sea after offshore interconnector cut

The Nato military alliance will 'enhance its military presence in the Baltic Sea' and back up Estonia's efforts to protect a remaining subsea cable still supplying electricity from Finland after suspected sabotage broke a high voltage interconnector between the two countries.

The Estlink 2 HVDC cable became disconnected from Estonia’s grid on Christmas Day and Finnish authorities subsequently said that they are investigating an oil tanker that was sailing from a Russian port amid suspicions of “grave sabotage” against the 170-kilometre interconnector.

The Eagle S oil tanker, which flies under the flag of the Cook Islands, is believed to belong to a so-called shadow fleet of ageing tankers which seek to evade Russian sanctions.

The ship was sailing from Saint Petersburg to Port Said in Egypt when it was detained, according to online marine tracking website, MarineTraffic.

The vessel was boarded by a Finnish coastguard crew, according to a statement by Helsinki police.

"From our side we are investigating grave sabotage," said Robin Lardot, director of the Finnish National Bureau of Investigation. "According to our understanding, an anchor... has caused the damage"."

Both the Estonian and Finnish governments stated that they had held emergency meetings on Thursday in order to assess the situation and the remaining cable, Estlink 1, will now be given special protection.

“We’ve decided to send our navy close to Estlink 1 to defend and secure our energy connection with Finland,” Estonian defence minister, Hanno Pevkur, posted on X today (Friday).

Spate of incidents

Several incidents of severed subsea communications and energy cables in both the Baltic and North Sea have led to growing suspicions about acts of intentional sabotage.

Such incidents seem to have proliferated since the start of the Russia-Ukraine conflict, raising fears that Moscow may be targeting the critical infrastructure of nations deemed to be hostile.

On November 17 and 18, two telecommunications cables were severed in the Baltic Sea, one between Finland and Germany, and another between Lithuania and Sweden.

The Balticconnector gas pipeline linking Finland and Estonia was also damaged in August, and similar incidents have occurred elsewhere, including a severed communications cable linking Scottish islands.

The Estlink 2 interconnector was the first HVDC power cable to be cut in European waters since the start of the Ukraine conflict.

Repairing it will take months, transmission system operator Fingrid said in a statement.

Nato role

NATO Secretary General Mark Rutte wrote in a post on the X platform that he had spoken with Finnish President Alexander Stubb about what he called "the ongoing Finnish-led investigation into possible sabotage of undersea cables".

"I expressed my full solidarity and support. NATO will enhance its military presence in the Baltic Sea,” Rutte stated.

The meetings that led to this launch were attended by industry representatives such as energy operators. The measures discussed include the development and possible deployment of innovative technologies to protect offshore infrastructure, including wind farms.

Nato allies have also committed to also establishing a Maritime Centre for the Security of Critical Undersea Infrastructure in Northwood, UK.

The European Union said it strongly condemned any deliberate destruction of the continent's infrastructure.

Moscow has strongly denied any involvement in incidents involving the breakage or cutting of subsea cables in European waters.

Russia launched a massive drone and missile attack on Ukraine's energy infrastructure on Christmas Day.