This latest episode of cable damage adds to a series of similar disruptions or suspected sabotage acts in the strategically important Baltic Sea.

NATO Secretary-General Mark Rutte on Friday said the alliance will increase patrols in the Baltic Sea region after Finland seized an oil tanker suspected of having damaged undersea power and internet cables 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.