Estlink 2, the direct current power link connecting Estonia and Finland's electricity systems, was shut down due to a fault. While the reason for the fault remains unknown, the Finnish press reports that both a Hong Kong-registered cargo ship and an oil tanker belonging to the so-called Russian shadow fleet were in the area at the time.

Nato also says it will enhance its military presence in the Baltic after a ship was suspected of sabotaging the Estlink 2 cable.

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.

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 cables there this week.

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.