Nations on the Baltic Sea, along with NATO, have stepped up security after a third incident of suspected sabotage to underwater infrastructure in a month.

Finnish police have reported finding the anchor responsible for severing an undersea internet cable connecting Finland to Estonia. Last month, Finland detained the Eagle S, an oil tanker transporting Russian oil,

Finnish police said on Tuesday they had recovered a lost anchor from the seabed as part of an investigation of suspected sabotage against power and internet cables in the Baltic Sea.

The anchor of the Eagle S oil tanker has been recovered from the bed of the Baltic Sea during an inquiry into the ship's possible involvement in sabotage of maritime energy and communication cables. The EU says the tanker belongs to the so-called Russian shadow fleet.