In November 2024, suspected sabotage damaged the C-Lion1 subsea fiber-optic cable between Finland and Germany in the Baltic Sea near Gotland, prompting a multinational investigation and rapid repair efforts.

Energy & Infrastructure AttacksCritical Infrastructure SabotageUndersea cables

AggressorDefense

Summary

In November 2024, two submarine fiber-optic cables in the Baltic Sea were damaged in suspected acts of sabotage. The C-Lion1 cable connecting Helsinki with Rostock experienced a disruption at 3 a.m. on November 18, which alarmed Finnish network operator Cinia. Another damaged cable was the BCS East-West cable between Lithuania and Sweden, with reported interruption on November 17. The Chinese-flagged bulk carrier Yi Peng 3, observed traveling along the paths of the cables, was pursued and monitored by Danish, Swedish, and German naval vessels when it anchored outside Danish waters in the Kattegat sea. Authorities from Denmark, Finland, Sweden, and Germany boarded the vessel during the investigation, but details remain undisclosed. Repair operations began on November 24 by the Cable Vigilance repair ship, concluding on November 28, restoring the connection after 11 days. European and NATO authorities suspect state-sponsored sabotage, with Russia and China under strong suspicion for similar incidents worldwide. NATO has since launched enhanced Baltic Sea surveillance missions using ships, drones, and aircraft to deter such attacks, while also working to improve rapid cable repair capacity amid a global shortage of specialized repair vessels. The incident underscores Europe’s vulnerability due to the critical reliance on undersea cables and insufficient protective and response measures.

Classification

Confidence: High

The article describes a concrete and specific incident of suspected state-sponsored sabotage of critical undersea cables attributed with suspicion to Russia and China, meeting criteria for aggressor activity. It also details NATO and European states' defensive measures including surveillance missions and rapid cable repair capacity improvements, constituting a defense preparation signal.

Source URL

https://archive.ph/00HJW

Open source

Provenance

Publisher: extension
Submitted: Feb 14, 2026, 12:22 UTC
Last updated: Nov 4, 2026, 08:35 UTC
Event time: Nov 18, 2024, 03:00 UTC

Published as a Defense Preparations signal with a public source and reviewer-approved assessment bands. See the methodology for how records are assessed.

Raw record

{
  "id": "d226aad0-ea7e-4e3b-acff-882a05f86e59",
  "url": "https://archive.ph/00HJW",
  "source": "extension",
  "status": "approved",
  "category": "Energy & Infrastructure Attacks",
  "subcategory": "Critical Infrastructure Sabotage",
  "incident_type": "Undersea cables",
  "country": "Denmark",
  "source_reliability": "B",
  "info_credibility": "3",
  "tags": [
    "submarine cables",
    "Baltic Sea",
    "sabotage",
    "undersea infrastructure",
    "China",
    "Russia",
    "NATO surveillance",
    "Cable Vigilance repair ship",
    "Yi Peng 3",
    "C-Lion1 cable",
    "critical infrastructure",
    "fiber-optic cables",
    "Denmark",
    "Finland",
    "Sweden",
    "Germany"
  ],
  "nodes": [],
  "countries": [],
  "where_text": "Undersea",
  "headline": null,
  "description": "In November 2024, two submarine fiber-optic cables in the Baltic Sea were damaged in suspected acts of sabotage. The C-Lion1 cable connecting Helsinki with Rostock experienced a disruption at 3 a.m. on November 18, which alarmed Finnish network operator Cinia. Another damaged cable was the BCS East-West cable between Lithuania and Sweden, with reported interruption on November 17. The Chinese-flagged bulk carrier Yi Peng 3, observed traveling along the paths of the cables, was pursued and monitored by Danish, Swedish, and German naval vessels when it anchored outside Danish waters in the Kattegat sea. Authorities from Denmark, Finland, Sweden, and Germany boarded the vessel during the investigation, but details remain undisclosed. Repair operations began on November 24 by the Cable Vigilance repair ship, concluding on November 28, restoring the connection after 11 days. European and NATO authorities suspect state-sponsored sabotage, with Russia and China under strong suspicion for similar incidents worldwide. NATO has since launched enhanced Baltic Sea surveillance missions using ships, drones, and aircraft to deter such attacks, while also working to improve rapid cable repair capacity amid a global shortage of specialized repair vessels. The incident underscores Europe’s vulnerability due to the critical reliance on undersea cables and insufficient protective and response measures.",
  "summary_short": "In November 2024, suspected sabotage damaged the C-Lion1 subsea fiber-optic cable between Finland and Germany in the Baltic Sea near Gotland, prompting a multinational investigation and rapid repair efforts.",
  "summary_extended": null,
  "actor_primary": "European and NATO authorities",
  "target_primary": null,
  "location_text": "Baltic Sea, near Swedish island of Gotland and Kattegat sea outside Danish waters",
  "location_region": null,
  "location_coordinates_lat": null,
  "location_coordinates_lon": null,
  "location_precision": "Approximate",
  "is_aggressor_signal": true,
  "signal_type": "DEFENSE_PREP_SIGNAL",
  "is_hybrid_war_signal": true,
  "classification_complete": true,
  "hybrid_signal_complete": true,
  "classification_confidence": "High",
  "classification_rationale": "The article describes a concrete and specific incident of suspected state-sponsored sabotage of critical undersea cables attributed with suspicion to Russia and China, meeting criteria for aggressor activity. It also details NATO and European states' defensive measures including surveillance missions and rapid cable repair capacity improvements, constituting a defense preparation signal.",
  "event_time_utc": "2024-11-18T03:00:00.000Z",
  "end_time_utc": "2024-11-28T23:59:00.000Z",
  "event_time_confidence": "exact",
  "created_at": "2026-02-14T12:22:55.036Z",
  "updated_at": "2026-11-04T08:35:32.139Z",
  "reliability_band": "strong",
  "location_precision_band": "approximate",
  "time_precision_band": "exact",
  "severity_band": "moderate",
  "attribution_confidence_band": "medium",
  "attribution_basis": "single_source"
}

Public assessmentReliability: StrongSeverity: ModerateAttribution: MediumSingle sourceTime: ExactLocation: Approximate

Source reliability

Info credibility

Event time

Nov 18, 2024, 03:00 UTC

End time

Nov 28, 2024, 23:59 UTC

Event time confidence

exact

Location

Baltic Sea, near Swedish island of Gotland and Kattegat sea outside Danish waters

Primary actor

European and NATO authorities

Country

Denmark

Tags

submarine cables, Baltic Sea, sabotage, undersea infrastructure, China, Russia, NATO surveillance, Cable Vigilance repair ship, Yi Peng 3, C-Lion1 cable, critical infrastructure, fiber-optic cables, Denmark, Finland, Sweden, Germany

Loading signal...

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