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.

After a fiber optic cable was damaged near Sweden, Latvia sent a patrol boat to inspect a suspicious vessel in the Baltic Sea. Sweden later said it seized a vessel believed to have carried out the sabotage.

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.

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

Swedish authorities have seized a ship over the “aggravated sabotage” of an undersea fibre-optic cable linking Latvia with a strategically important island in Sweden.

The Arelion submarine cable, which connects the Swedish island of Gotland to Lithuania, and the C-Lion 1 submarine communications cable that runs between Finland's capital Helsinki and the German city of Rostock were also damaged in mid-November near Sweden's territorial waters.

Sweden detained a vessel suspected of damaging a subsea data cable connecting it with Latvia, the third such incident in the Baltic Sea in the past three months.

A subsea data cable between Latvia and Sweden was damaged early Sunday, sparking a criminal investigation, a third such incident in the Baltic Sea in the past three months.

Swedish authorities have seized a ship suspected of damaging a data cable running under the Baltic Sea to Latvia. The Vezhen - a Maltese-flagged ship - is now anchored outside the Swedish port of Karlskrona.

Latvia said it had dispatched a warship on Sunday after damage to a fibre optic cable to Sweden that may have been "due to external factors".

Several undersea cables running under the surface of the Baltic Sea have been damaged in suspected sabotage incidents in recent months.