Damage to data cables between Finland and Sweden in December 2024 caused internet outages. While sabotage was initially suspected, the Finnish agency reported the damage resulted from construction accidents. Previous November incidents involving Baltic Sea cables are under investigation for possible sabotage linked to foreign vessels. NATO stresses the need to protect undersea infrastructure amid hybrid threats.

In November 2024, two fiber optic data cables in the Baltic Sea were damaged, followed by another incident in early December 2024 involving a land cable connecting Finland and Sweden near Helsinki. The Finnish Transport and Communications Agency (Traficom) stated that the cables were accidentally cut during construction work, and repairs have been completed. Initial suspicions of sabotage by Swedish Civil Protection Minister Carl-Oskar Bohlin were not supported by police investigations, which found no grounds for criminal inquiry. Earlier incidents in November involved cables between Sweden and Lithuania and between Sweden and Germany, with unclear causes but suspected sabotage. Swedish authorities are investigating possible sabotage, focusing on a Chinese ship named 'Yi Peng 3' that passed near the damaged cables at the time. Poland has proposed joint Baltic Sea monitoring by coastal states to protect underwater infrastructure. NATO Secretary-General Mark Rutte emphasized the urgency of securing data cables against sabotage and hybrid attacks, noting the increased use of sabotage, energy extortion, and cyberattacks related to the ongoing Russian war in Ukraine. NATO plans to discuss hybrid threats at an upcoming meeting.