Police say a Norwegian-owned and Russian-crewed ship that authorities suspect may have been involved in damage to an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland has been stopped off Norway.

The NATO military alliance is ramping up efforts to protect undersea cables in the region amid growing concerns of Russian sabotage and spying. View on euronews

After a series of suspected undersea cable cuttings, NATO has launched a new surveillance and deterrence mission to protect critical infrastructure under the Baltic Sea.

Norwegian police say they had seized and boarded a Norwegian ship with an all-Russian crew on suspicion of involvement in causing damage to a telecoms cable in the Baltic Sea, the second vessel to be named by investigators in the case.

Nato countries have stepped up patrols to protect critical underwater infrastructure in the Baltic Sea, which is bordered by eight countries, and other waters. A Royal Navy submarine was ordered to surface last November close to a suspected Russian spy ship which was loitering over undersea infrastructure in UK waters.

Estonia's defence minister on Wednesday said ships may have to pay a fee to use the Baltic Sea to cover costs of protecting undersea cables.

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.

Norwegian authorities detained the Silver Dania vessel with a Russian crew on Jan. 30 on suspicion of it damaging an undersea fiber-optic cable linking Latvia and Sweden, the Norwegian police announced.