Footage of Finland detaining a Russian ship that committed sabotage in the Baltic Sea

Finnish authorities detained a ship linked to neighbouring 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 in the region.

Finnish police and border guards boarded the vessel, the Eagle S, early Thursday and took over the command bridge, Helsinki Police Chief Jari Liukku told a news conference.

The vessel was being held in Finnish territorial waters, police said.

The Eagle S is flagged in the Cook Islands, but was described by Finnish customs officials and the European Union's executive commission as part of Russia's shadow fleet of fuel tankers.

Those are aging vessels with obscure ownership, acquired to evade Western sanctions amid the war in Ukraine and operating without Western-regulated insurance.

Russia's use of the vessels has raised environmental concerns about accidents given their age and uncertain insurance coverage.The Eagle S's anchor is suspected of causing damage to the cable, Yle television reported, relying on police statements.

The EU's foreign policy chief, Kaja Kallas, said in a statement that the incident was “the latest in a series of suspected attacks on critical infrastructure” and commended the Finnish authorities “for their swift action in boarding the suspected vessel."

The ship “is part of Russia’s shadow fleet, which threatens security and the environment, while funding Russia’s war budget,” said Kallas, a former Estonian prime minister.

"We will propose further measures, including sanctions, to target this fleet.”

The Estlink-2 power cable, which brings electricity from Finland to Estonia across the Baltic Sea, went down on Wednesday.

The incident follows damage to two data cables and the Nord Stream gas pipelines, both of which havebeen termed sabotage.

The Estonian government met in emergency session over the incident.

The shadow tankers “are helping Russia to earn funds that will aid Russian hybrid attacks,” Prime Minister Kristen Michal said at a news conference.

“We need to improve the monitoring and protection of critical infrastructure both on land and on sea.”