Police and media reports say that Finnish authorities have detained a Russia-linked ship as they investigate whether it damaged a Baltic Sea power cable and several data cables.

Damage to the power cable in the Baltic Sea is the latest in a spate of murky disruptions to undersea cables that have put European authorities on high alert.

The Finnish authorities seized an oil tanker on Thursday on the suspicion that it was involved in cutting vital undersea cables and said the ship might have been part of Russia’s “shadow fleet,” aimed at evading Western sanctions.

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.

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