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

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.

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.

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

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 cables, while alliance member Estonia launched a naval operation to guard a parallel electricity link.

Finland has seized an oil tanker suspected of having severed undersea power and internet cables, with Finnish authorities saying the vessel may have been part of Russia's "shadow fleet" of ships aimed at skirting Western sanctions.

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.

The Finnish authorities seized an oil tanker on Thursday on the suspicion that it was involved in cutting vital undersea cables and said the ship might have been part of Russia’s “shadow fleet,” aimed at evading Western sanctions.