2024 Baltic Sea submarine cable disruptions

On 17 November 2024, two submarine telecommunication cables — the BCS East-West Interlink and C-Lion1 cables — were disrupted at the same location in the Baltic Sea. The simultaneous disruption of both cables in the same area prompted accusations from European government officials and NATO member states of hybrid warfare and sabotage as the cause of the damage.

The BCS East-West Interlink is a 218 km (135 mi) long submarine data communication cable that runs through the Baltic Sea, built in 1997 by Alcatel and owned by Arelion. It connects Sventoji in Lithuania to Katthammarsvik on the east coast of the Swedish island of Gotland.^[1] The C-Lion1 is a submarine communications cable between Finland and Germany. The cable is owned and operated by the Finnish telecommunications and IT services company Cinia Oy, and is the first direct communications cable between Finland and Central Europe following its start of operations in May 2016.^[2][3]

Hundreds of undersea cables are cut or disrupted annually, due most frequently to unintentional damage from fishing equipment or the anchors of ships.^[4][5] According to a July 2024 report by the Internet Society, dragging ship anchors are "a common source of submarine cable cuts".^[6] In 2017, the United States Director of National Intelligence found that "the majority of disruptions [to undersea cables] are caused by human activity (e.g., fishing, anchoring, dredging) and natural disasters".^[7] A year before the 2024 Baltic Sea submarine cable disruptions, a similar undersea infrastructure disruption event, the Balticconnector incident, occurred when the Chinese ship Newnew Polar Bear dragged its anchor across the seabed, damaging the pipeline and submarine cables.^[8]

On Monday, 18 November 2024,^[9] the telecommunications company Telia Lithuania announced that the BCS East-West Interlink submarine cable between Lithuania and Sweden had been "cut" on Sunday morning at around 10 a.m. local time.^[10] At around the same time, the submarine cable C-Lion1 for data communication between Finland and Germany was cut in the same region of the Baltic Sea. As a result, both of their telecom services were disrupted.^[11][12] The C-Lion1 fault was discovered off the coast of the Swedish island of Öland.^[13] The two faults were detected about 97–105 kilometres (60–65 mi) apart from each other.^[14] The BCS East-West cable is at a depth of 100–150 metres (330–490 ft) and C-Lion at 20–40 metres (66–131 ft) deep.^[15]

An Arelion spokesperson described the damage to the BCS East-West Interlink cable as "...not a partial damage. It’s full damage”.^[16] At the time of the incident, the cable provided about 1/3rd of the internet capacity of Lithuania.^[14]

According to C-Lion1 operator Cinia Oy, the cable was severed by an outside force.^[17] Cinia chief executive Ari-Jussi Knaapila stated that the company was in the process of conducting physical inspections at the site of the fault.^[14][18][19]

The Foreign Ministers of Germany and Finland issued a joint statement expressing "deep concern" over the C-Lion1 cable's disruption, and expressed suspicion over possible hybrid warfare conducted by Russia, causing the disruptions in the midst of the Russian invasion of Ukraine and elevated tension against NATO member states.^[16][20]

German Federal Defense Minister Boris Pistorius called the incident an act of sabotage.^[9] He further stated that "no one" believed that the cables were cut accidentally.^[16]

The Lithuanian Armed Forces stated that NATO members were in correspondence with one another to determine the cause of the disruptions.^[16] The Lithuanian Naval Force announced increased surveillance of its waters in response to the damage and would discuss further measures with Lithuania its allies.^[9]

European governments accused Russia of escalating hybrid attacks on Ukraine's Western allies, but not directly accusing Russia of destroying the seacables.^[21]

Kremlin spokesman Dmitry Peskov rejected suspicions and called it "absurd", accusing Russia without evidence^[21]

On 19 November 2024 the Royal Danish Navy observed the Chinese cargo ship Yi Peng 3 in the Baltic Sea after it was suspected to be involved in the sabotage.^[22][23] The detention of the Chinese vessel was the first enforcement action under the Convention for the Protection of Submarine Telegraph Cables since the Transatlantic cables incident of 1959.^[24] Since 20 November 2024, the ship is stationed at a sea position in the Kattegat off anchor and is guarded by the Royal Danish Navy.

Yi Peng 3 left the Russian Baltic harbour Ust-Luga on 15 November 2024. The information about the destination of the ship offered by media outlets varied, the most frequently mentioned being Port Said, Egypt. According to the analysis provider MarineTraffic, the destination was unknown upon departure.^[25] On 17 November, between 1:30 a.m. (UTC) and 11:19 a.m. the ship passed the Swedish island of Gotland. Yi Peng 3 crossed BCS East-West. At around 10 a.m., the Lithuanian telecom provider Telia in Vilnius received a fault report: the connection between Šventoji, Lithuania, and Gotland, Sweden had been severed. The ship crossed several times over the position of damage of the two cables.^[26][27] The Yi Peng 3 continued its journey south. After Gotland, the freighter switched off its automatic identification system (AIS) signal for 7.5 hours. At 22:41 UTC the ship switched AIS back on and was located south of the Swedish island of Öland.^[26]

Three hours later, at 2 a.m. (UTC) on 18 November, the Finnish network provider Cinia reported a loss of data traffic via C-Lion1. It became clear that the cable between Gotland and Öland was damaged. In this area the Yi Peng 3 was traveling without an AIS signal.^[26] The Danish broadcaster DR reported that the anchor of the Yi Peng 3 was said to be damaged – according to NZZ an indication that the freighter could have destroyed the cables.^[25]

The Swedish Prosecution Authority opened an investigation into "sabotage" regarding the disruptions.^[16] According to the Swedish Navy, it had an "almost 100% identification" of the ships that were in the area of the two cable breaks.^[15] The navy is using a remote-controlled submarines to investigate the southern site of the two cables to support the Swedish prosecutor and police with their investigations.

Keskusrikospoliisi (KRP), Finland's national bureau of investigation opened a criminal investigation into the rupture of the C-Lion1 cable on suspicion of "aggravated criminal mischief and aggravated interference with communications."^[28]

• 2008 submarine cable disruption
• 2011 submarine cable disruption
• Nord Stream pipelines sabotage