Swedish authorities say they have detected a Chinese ship moving near two telecoms cables that failed within hours of each other on the Baltic Sea bed in recent days.
Prosecutors in Stockholm have launched a preliminary investigation into suspected sabotage, hours after Germany dubbed the cable failure part of a “hybrid operation”.
On Sunday morning at about 10am, Swedish authorities registered problems with a data cable under the Baltic Sea from the Öland island to Lithuania. At 4am on Monday, telecoms operators in Finland and Germany reported problems with another cable called C-Lion-1.
Both cables were damaged in the Swedish economic zone, prompting prosecutors in Stockholm to take the investigation lead.
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They have not ruled out the involvement of a passing ship or trawler anchor in the incidents and have requested the Swedish navy send ships to inspect the scene. On Tuesday Sweden’s Säpo security police also joined the investigation.
“This is, of course, potentially very serious,” said Carl-Oskar Bohlin, Sweden’s civil defence minister, confirming “ship movements that correspond” to the cable breaks.
German defence minister Boris Pistorius said “nobody believes that these cables were severed by accident”.
“Even without concrete knowledge of the perpetrator,” he said, “we have to call this a hybrid operation and must assume, without being certain, that this was sabotage.”
In an unusual joint statement, the German and Finnish foreign ministries condemned “hybrid warfare by malicious actors”.
At the weekend, Danish military ships followed a Chinese vessel, Yi Peng 3, through the Baltic, leading to speculation of a link to the incident.
A year ago Finland found that another Chinese ship called Newnew Polar Bear damaged a Baltic gas pipeline. The Newnew Polar Bear was flagged in Hong Kong and its owner, a Chinese logistics company with reportedly strong Russian connections, insisted the damage was accidental.
Finnish firm company Cinia, which built the C-Lion-1 cable, said a ship it dispatched to inspect the cable reported it was “completely severed” in a way that suggested less natural wear and tear but “some other external force”.
The cable runs 1,173km between Santahamina in Helsinki and Rostock in Germany and is the only data communications cable running directly from Finland to central Europe.
Lithuanian telecoms company Telia Lietuva said the damage to the other cable to Sweden happened in a 10sq m crossing with the C-Lion-1 cable.
“Since both are damaged, it is clear that this was not an accidental dropping of one of the ship’s anchors, but something more serious could be going on,” said Andrius Šemeškevičius, Telia Lietuva’s chief technology officer.
While the damage disrupted some data transfers, it did not endanger internet connections or online security in any of the countries.
Finland’s national cyber security centre said it was “certainly possible” that the cable had broken due to wear and tear or an accident.
“Cables at the bottom of the sea are exposed to all kinds of weather phenomena as well as shipping,” said Samuli Bergström, a director of Finland’s cyber security centre. “They undergo various maintenance procedures continuously.”
The latest cable breaks come days after a three-ship Russian flotilla, including a warship and a suspected spy ship, was monitored in Irish-controlled waters.
German security expert Henrik Schilling said it was “impossible to protect all critical infrastructure” – in particular undersea cables and pipelines.
“It would make sense to make better use of the sensors already installed on the respective infrastructure,” said Dr Schilling of the Institute for Security Policy at Kiel University. “Redundancies should be considered when building such infrastructure, with closer co-operation between authorities, operators and the military or police.”
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