A Bulgarian ship has been released after Swedish authorities cleared it of deliberately sabotaging an underwater cable in the Baltic Sea. NATO has moved to protect Baltic Sea cables amid concerns of Russian tampering.

Swedish prosecutors on Monday ruled out sabotage in the case of a damaged undersea cable and said they were releasing a Bulgarian ship seized in connection with the incident, determining the damage was accidental.

A Norwegian-owned and Russian-crewed ship that authorities initially suspected may have been involved in damage to an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland has been released.

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.

Intelligence officials in the U.S. and Europe have suggested that recent incidents damaging critical cables in the Baltic Sea were accidental, according to a Washington Post report. Western geostrategic self-deception has overly emphasized fears of escalation and cornering Russia.

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.

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.