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.

Swedish authorities boarded a Maltese-flagged ship seized in connection with the latest breach of cables running along the bottom of the Baltic Sea to begin an investigation into the matter, the country's security police said on Monday.

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.

A Bulgarian shipping company on Monday denied that one of its ships had intentionally damaged an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland.

NATO is deploying eyes in the sky and on the Baltic Sea to protect cables and pipelines that stitch together the nine countries with shores on Baltic waters

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.

There has been a sharp rise in damage to undersea cables in the Baltic, with at least 11 incidents reported since October 2023.

NATO is ratcheting up its guard against suspected attempts to sabotage underwater energy and data cables and pipelines that crisscross the Baltic Sea.

Swedish authorities boarded a vessel suspected of being involved in an earlier underwater sabotage of cables in the Baltic Sea on Monday.