Police from Finland have detained the Russian crew of a tanker suspected of cutting a telecommunication cable in the Baltic Sea.
Finnish authorities seized the Fitburg, a St Vincent and Grenadines-flagged cargo ship, on Wednesday. It had been travelling from St Petersburg to Haifa,Israel.
The ship's crew consists ofRussian, Georgian, Kazakh and Azerbaijani sailors, according to police, who are investigating the case as aggravated criminal damage and suspected sabotage.
The Fitburg, which was detained in Finnish waters while its anchor was down, is suspected of being "responsible for damage to [a] cable" running between Helsinki and Tallinn in the Gulf of Finland.
The incident occurred in the Baltic Sea, which has seen a huge increase in suspected sabotage attacks on undersea cables since the start of theRussia-Ukraine war.
Western officials suspect the attacks are being carried out as part ofVladimir Putin's hybrid war campaign, which is designed to punish the West for its military support of Kyiv.
Elisa, the Finnish telecoms operator and owner of the cable, said the damage had "not affected the functionality of [its] services in any way".
The company said it had informed Finnish authorities as soon as it detected a fault in the cable earlier on Wednesday.
A Finnish police spokesman said: "At this stage, the police are investigating the incident as aggravated criminal damage, attempted aggravated criminal damage, and aggravated interference with telecommunications."
The Estonian justice ministry said a second telecoms cable connecting the country toFinlandfailed temporarily on Wednesday, although it was not confirmed that it was connected to the Elisa incident.
Alar Karis, the Estonian president, said onsocial mediasite X: "I'm concerned about the reported damage ... hopefully it was not a deliberate act, but the investigation will be clarified."
Alexander Stubb, the Finnish president, said: "Finland is prepared for security challenges of various kinds, and we respond to them as necessary."
The case under investigation is reminiscent of an incident in December 2024,when Finnish authorities boarded the Eagle S, an oil tanker linked to Russia. They suspected that its anchor had damaged five cables in the Baltic.
Finland's attempt to prosecute the Eagle S's crew collapsed. A court in Finland ruled that prosecutors had not been able to prove that the crew intentionally damaged the cables. The fact that the ship had been stopped in international – rather than Finnish – waters, led to a dispute about jurisdiction.
The Baltic Sea is crossed by as many as two thousand ships per day and has become one of the most fraught battlegrounds between Nato allies and Russia.
In an interview with the Telegraph earlier this year, a top German naval officer said it could be very difficult to prove that a rogue crew had dropped and dragged an anchor on purpose.
"If you don't have a well-trained crew, it might drop the anchor because they've been told to wait three days, or because there is a lack of orders, or because there is bad weather, and not realise there is a cable underneath them," said Stephan Haisch, a Rear Admiral in the Bundeswehr, the German armed forces.
"It's stupid, because the cables are marked on the nautical chart, but they just don't know. It can happen – but it is really stupid and shortsighted," he added.
Another problem is confirming whether a ship has any ties to Russia, as in many cases the vessels will sail under the flag of an obscure country with no obvious Russian links.
In the case of the Fitburg, for example, the ship was sailing under the flag of St Vincent and Grenadines, a former UK Overseas Territory and island nation in the eastern Caribbean.
According to London Stock Exchange Group data, the owner of the Fitburg is Fitburg Shipping Company Ltd and the manager is Albros Shipping and Trading Ltd.
In addition to cutting cables, Russia-linked ships are suspected of carrying out surveillance on Nato ships and warplanes. They are typically part of Moscow's infamous shadow fleet, a group of rusty, poorly maintained ships which sail under foreign flags to evade sanctions.
When the Eagle S was boarded in a separate incident in Danish waters, the crew was unable to explain why it was carrying specialist equipment designed for such surveillance.
An ongoing Nato mission to crack down on suspicious Russia-linked ships in the Baltic Sea is being led by Germany, which last year opened a new headquarters in Rostock, on the country's northern coast.
Known as CTF Baltic, [Commander Task Force Baltic], the new Rostock headquarters has angered Moscow, which claims it violates a 1990s-era treaty that banned the stationing of new Nato forces in the former communist state of East Germany.
"I could say that people are bothered by [the task force] in Russia, and that is a good sign, if people are bothered in Russia, because then we have achieved a certain effect," said Rear Admiral Haisch.
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