Finnish authorities say they have opened an investigation into the rupture of a data cable under the Baltic Sea, adding to a Swedish probe into the possible sabotage of that link and another cable.

Two undersea fibre-optic communications cables in the Baltic Sea, including one linking Finland and Germany, were severed, raising suspicions of sabotage by bad actors, countries and companies involved said on Monday.

The "Arelion" submarine cable between the Swedish island of Gotland and Lithuania has been damaged since Sunday morning, a spokesman for the Lithuanian branch of the operator Telia said Tuesday. Internet traffic has been redirected to other international links, Audrius Stasiulaitis said.