Finnish investigators probing the damage to a Baltic Sea power cable and several data cables said they found an anchor drag mark on the seabed, apparently from a Russia-linked vessel that has already been seized.

Finnish police said on Sunday they had found tracks that drag on for dozens of kilometres along the bottom of the Baltic Sea where a tanker carrying Russian oil is suspected of breaking a power line and four telecoms cables with its anchor.

Permanent representatives of NATO member countries met in Brussels today and agreed on measures to enhance the Alliance's presence in the Baltic Sea and protect critical undersea infrastructure following an incident involving damaged undersea cables.

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.

Finnish police have discovered traces on the bottom of the Baltic Sea stretching for dozens of kilometers. It is believed that a tanker, which was carrying Russian oil, severed a power line and four telecommunications cables with its anchor,

Police and media reports say that Finnish authorities have detained a Russia-linked ship as they investigate whether it damaged a Baltic Sea power cable and several data cables.

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.