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.

In just three months, three incidents of damage to Baltic Sea underwater cables have taken place. While accidential cable slices are common, the cluster raises suspicion.

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.

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.

Sweden has opened a preliminary investigation into suspected aggravated “sabotage” and ordered the detention of a vessel in the Baltic Sea suspected of damaging an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland earlier that day.

Sweden is investigating damage to a data cable linked to Latvia, the latest breach in the Baltic Sea region where European authorities are on high alert.

Norway has detained the Silver Dania on suspicion of involvement in damaging a fiber optic cable in the Baltic Sea. The ship's crew are Russians, Dagbladet reports. Norwegian police said they had seized the Silver Dania based on a legal request from Latvia and a court order.