The Baltic Sea region is on high alert as fears grow that Russia could target undersea cables as part of a wider campaign of so-called "hybrid warfare".

The Nordic country has opened an investigation into the damage, just weeks after NATO stepped up its military presence in the area following a series of similar incidents.

ABOARD A FRENCH NAVY FLIGHT OVER THE BALTIC SEA, Jan 28, (AP): With its powerful camera, the French Navy surveillance plane scouring the Baltic Sea zoomed in on a cargo ship plowing the waters below - closer, closer and closer still until the camera operator could make out details on the vessel's front deck and smoke pouring from its chimney.

Russia has condemned the Western alliance for ramping up its naval presence in the so-called 'NATO lake' after alleged sabotage by Moscow-linked vessels.

NATO on Tuesday launched operation Baltic Sentry to deter further attempts to damage critical underwater infrastructure in the Baltic Sea. Secretary General Mark Rutte announced the operation on Tuesday in a joint press conference with Finland President Alexander Stubb and Estonia Prime Minister Kristen Michal at the Baltic Sea NATO Allies Summit held in Helsinki,

The mission, dubbed Baltic Sentry, follows worry over increased Russian military activity near key undersea communication cables.

A senior Russian official has said that Moscow will counter any moves by Western military alliance NATO to dominate the Baltic Sea. Deputy Foreign Minister Alexander Grushko told the Russian television channel Rossiya-24 on Friday that the Western alliance's decision to increase patrols around the Baltic was further proof of NATO's "desire to turn the Baltic Sea into a NATO lake.

Cables deep under the Baltic Sea keep getting damaged - here is what Nato is doing to protect them - Nato is deploying eyes in the sky and on the Baltic Sea to protect cables and pipelines

German Chancellor Olaf Scholz highlights risks from Russia's shadow fleet amid undersea cable damage, stressing NATO's role in Baltic security.

The Danish PM's tour of three capitals betrayed the nervousness felt in Denmark over Trump's repeated comments.

NATO Secretary-General Mark Rutte and Danish Prime Minister Mette Frederiksen agreed at a meeting on Tuesday that allies need to focus on strengthening defences in the Arctic, a source familiar with the talks told Reuters.