The European Union vowed on Friday to increase security in the Baltic Sea as the Swedish authorities said they were investigating a new cable break, the latest example of damage to underwater infrastructure in the region.
The European Commission, the bloc’s executive arm, said it would take new steps to prevent and detect threats to submarine cables, which carry internet traffic.
The severing of several undersea cables in the Baltic Sea in recent months has raised concerns that Russia is using the moves to retaliate against NATO countries that have supported Ukraine. Alliance officials have pointed to Russia as a possible culprit, but have said that it is difficult to prove.
NATO has also stepped up its military presence in the area with a new patrol and surveillance operation, called Baltic Sentry, aimed at protecting infrastructure in the sea.
A spokesman for the Swedish police, Mathias Rutegard, declined to comment on the ownership of the latest damaged cable, but it appeared to be the C-Lion1, a major telecommunications line that runs between Finland and Germany, after its Finnish owner, Cinia, said on Friday that it had detected damage. The cable connects the telecommunications networks of Central Europe to the Nordic countries.
The company said in a statement that the damage was minor and that telecommunications were transmitting as normal, but this would be the third time in recent months that the C-Lion1 had been damaged.
It was unclear Friday what had caused the damage. Cinia said details were being investigated.
The Swedish police have opened a preliminary investigation, Mr. Rutegard said, because the damage occurred in the country’s Exclusive Economic Zone, an area where Sweden has rights but which is beyond its territorial waters.
Prime Minister Ulf Kristersson of Sweden said on Friday that his government took “all reports of possible damage to infrastructure in the Baltic Sea very seriously.” Such reports, he said, had to be seen in light of the “serious security situation that prevails.”
The Swedish Coast Guard was informed of the cable break on Thursday and was heading to the area off the eastern island of Gotland, Mattias Lindholm, a spokesman for the service, said.
Cinia, which is majority-owned by the Finnish state, said it had asked the Finnish criminal authorities to investigate. Finland’s interior minister, Mari Rantanen, told the Finnish public broadcaster Yle on Friday that the authorities were still waiting for answers, but that “the possibility of an accident is very small.”
Telecommunications using the C-Lion1 cable, which has been in service since 2016, were interrupted in December, Cinia said, a disruption it attributed to a probable cable cut in the Gulf of Finland. Another break that downed services was detected in late November, Cinia said, east of the Swedish island Oland.
The Finnish authorities in December seized an oil tanker suspected of cutting several vital underwater cables and accused it of being part of Russia’s “shadow fleet. Western officials have said they believe Russia has been using such tankers to elude sanctions. Analysts have said that if Russia is also using shadow fleets to sabotage vital infrastructure in Europe, it would be an escalation in Moscow’s conflict with the West.
Sweden, NATO’s newest member, said in January that it was investigating another incidence of damage to an undersea cable running between Sweden and Latvia. The Swedish authorities boarded a cargo ship it suspected of committing “gross sabotage.”
