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.

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.

The Joint Expeditionary Force (JEF), consisting of forces from 10 Northern European countries, has enhanced the protection of undersea cables in the Baltic Sea and the monitoring of the Russian "shadow fleet,

Two undersea telecommunications cables that were damaged in the Baltic Sea on Dec. 25 appeared to have been torn apart by a strong external force, Finland's Elisa said on Monday, adding that they had now been repaired.

Finnish authorities have found and retrieved the anchor of the Eagle S tanker, suspected of damaging cables in the Baltic Sea. Investigators will begin inspecting it on Tuesday. Finnish radio Yle reported that the tanker Eagle S's anchor was located at the bottom of the Gulf of Finland and brought to the surface.