Nato has said it will enhance its military presence in the Baltic Sea, and Estonia has sent a patrol ship to protect its Estlink1 undersea power cable, after Russia was accused of sabotaging its main power link in the Gulf of Finland.

A ship named as Eagle S is suspected of damaging the Estlink 2 cable and Finnish coast guard crew have boarded the oil tanker and steered it into Finnish waters.

The EU said the Eagle S was part of “Russia’s shadow fleet” and the failure of the undersea cable was the “latest in a series of suspected attacks on critical infrastructure”.

Estonian Defence Minister Hanno Pevkur said the Raju had set sail early on Friday and he believed Finland would join the operation to protect the remaining cable.