Finland's National Bureau of Investigation (NBI) announced on Tuesday that it has opened an investigation into what caused damage to a telecommunications cable in the Baltic Sea.
The C-Lion1 submarine telecoms cable was damaged early on Monday morning.
Swedish police are also investigating what caused damage to another telecoms cable which runs between Sweden and Lithuania that occurred in the Baltic on Sunday.
Finnish and Swedish authorities are establishing a joint investigative team to look into the incidents, according to the head of the NBI's investigation department, Timo Kilpeläinen.
On Tuesday morning, German Defence Minister Boris Pistorius told news agency Reuters that he suspected the damage was caused by sabotage. The companies that own the cables have said it would be nearly impossible to damage them without some external force.
Finnish Prime Minister Petteri Orpo (NCP) said on Tuesday that it was not time to draw conclusions, however.
"It is not yet possible to say whether it was sabotage. That's why I'm not jumping to conclusions yet," he told reporters at Aalto University in Espoo.
According to Orpo, a more detailed assessment of the situation will be made about the situation will be made after authorities investigate.
Orpo said he has discussed the matter with German Chancellor Olaf Scholz, Swedish PM Ulf Kristersson and Estonian PM Kristen Michal.
The Finnish PM noted that Baltic Sea region states have been preparing ways to protect their critical infrastructure. In October 2023, a gas pipeline between Finland and Estonia, the so-called Balticconnector, was damaged after being struck by an anchor from a Chinese freighter.
It is possible that the damage on Monday was accidentally caused by an anchor or fishing gear, but some experts have suggested that scenario is unlikely.
In September, news network CNN reported that US authorities had warned of a risk that Russia would begin sabotaging sub-sea cables belonging to the United States and its allies.
Missing vessel beacons
On Sunday, hours before the cables were damaged, navigational beacon transmitters of at least four vessels in the area had been periodically turned off, according to the website Marine Traffic.
The beacon signal of one of those vessels — the Chinese-flagged cargo ship Yi Peng 3 — went missing during all of Sunday evening until around 1am on Monday, as it sailed in the vicinity of the cable.
The cable belongs to the Finnish state majority-owned firm Cinia.
At a press conference on Tuesday, Cinia's CEO Ari-Jussi Knaapila said that transmissions on the cable were disrupted at 4:04 am on Monday, and that 11 seconds later, the link was completely cut.
The CEO said that a repair vessel is scheduled to arrive at the site of the damaged cable on Sunday. He said repairs will take a few days, but effort's duration will depend on weather and wind conditions.
According to Knaapila, the area where the Sweden-Lithuania telecoms cable was damaged was dozens of nautical miles away from the damaged portion of the C-Lion1 cable.
He said that because of the distance, the damage to each of the cables could not have been caused by a single incident or action. He noted that Cinia was informed about the Sweden-Lithuania cable damage just after noon on Monday.
On Tuesday, Finnish Defence Minister Antti Häkkänen said that he briefly discussed the cable damage issue at a defence ministers' meeting in Brussels, including with the defence ministers of Sweden and Germany.
However, Häkkänen did not offer speculation about which vessel could be responsible for the damage, nor what was known about its activities in the area.
"The investigation is ongoing. We should now find out exactly who was [at the site of the damaged cable]," he said at a press conference.
Edited on 20 November to note that the Sweden-Lithuanian cable was broken on Sunday.