An undersea fibre optic cable between Germany and Finland has stopped working and might have been deliberately cut by an unknown party, according to authorities.
The 729 mile (1,173km) C-Lion1 cable under the Baltic Sea from Helsinki to Rostock went offline just after 2am GMT on Monday.
The outage was reported by Finnish state-controlled cyber security and telecoms company Cinia.
A physical inspection has not yet been done but the abrupt nature suggests it was completely severed by an outside force, said chief executive Ari-Jussi Knaapila.
Germany and Finland‘s foreign ministers said they were “deeply concerned” and it “immediately raises suspicions of intentional damage”.
A joint statement said: “Our European security is not only under threat from Russia’s war of aggression against Ukraine, but also from hybrid warfare by malicious actors.
“Safeguarding our shared critical infrastructure is vital to our security and the resilience of our societies.”
Cinia said “corrective measures” were under way and a repair ship was being prepared.
The damage to the fibre optic cable could take around five to 15 days to fix, Mr Knaapila told reporters.
He said the damage occurred near the southern tip of Sweden’s Oland island and that Cinia was working with authorities to investigate.
The cable links central European telecoms networks to Finland, other Nordic countries and Asia.
A Chinese ship was blamed for damaging another cable, the Balticconnector gas pipeline, last year. Pic: Finnish Border Guard/Reuters
Another submerged gas line and several telecoms cables were seriously damaged last year in the Baltic Sea.
A Chinese container ship dragging its anchor was named as prime suspect by Finnish police. However, they have not said if they think the damage was intentional.
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Two years ago, a gas pipeline from Russia to Germany – the Nord Steam – was also damaged by explosions.
Many suspected Moscow of foul play but German authorities are still investigating the case.