Damage to the power cable in the Baltic Sea is the latest in a spate of murky disruptions to undersea cables that have put European authorities on high alert.

Police and media reports say that Finnish authorities have detained a Russia-linked ship as they investigate whether it damaged a Baltic Sea power cable and several data cables.

NATO said on Friday it would boost its presence in the Baltic Sea after the suspected sabotage this week of an undersea power cable and four internet lines, while alliance member Estonia launched a naval operation to guard a parallel electricity link.

Finland’s leaders are calling for more NATO protection against alleged Russian sabotage of critical infrastructure.

The Estlink 2, an undersea power cable linking Finland and Estonia, was seriously damaged on Christmas Day. Authorities are investigating the incident as a possible act of sabotage.

The Eagle S is flagged in the Cook Islands but was described by Finnish customs officials as a suspected part of Russia’s so-called shadow fleet.

Finland's prime minister, Petteri Orpo, said the outage had not affected the country's electricity supplies. However, Reuters reports that the capacity between the countries was reduced

NATO Secretary-General Mark Rutte says the military alliance will step up patrols in the Baltic Sea area as Finnish investigators work to establish whether a ship linked to Russia sabotaged undersea c