FRANKFURT, Germany — Finnish authorities detained a ship linked to neighboring Russia as they investigate whether it damaged a Baltic Sea power cable and several data cables, police said, in the latest incident involving disruption of key infrastructure.

The Estlink 2, an undersea power cable linking Finland and Estonia, was seriously damaged on Christmas Day. Authorities are investigating the incident as a possible act of sabotage.

It's believed the anchor of the Eagle S caused damage to a key electric cable which carries power from Finland to Estonia, across the Baltic Sea.

Russia’s top security agency says that it has arrested several suspects accused of involvement in an alleged Ukrainian plot to assassinate senior military officers.

Russia's Federal Security Service (FSB) said on Thursday (December 26) that it had foiled several plots by Ukrainian intelligence services to kill high-ranking Russian military officers and their families in Moscow,

Russia launched aerial attacks on Ukraine’s energy sector “on a massive scale” overnight into Wednesday, local authorities said, with explosions reported across the country amid intensified bombardments that have left Ukraine in a precarious position while the war grinds into a third winter.

Russia attacked Ukraine's energy system and some cities with cruise and ballistic missiles plus drones, Ukraine's President Volodymyr Zelenskiy said.

Ukraine's air force says it detected 184 missiles and drones, causing damage to energy infrastructure across the country.