Finnish authorities have detained a Russia-linked ship as they investigate whether it damaged a Baltic Sea power cable and several data cables, according to police and news media reports, 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 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.

Kazakh authorities have recovered the flight data recorder and an investigation is under way. Shortly after the crash, reports from Russian state-controlled TV said the most likely cause was a strike from a flock of birds.

An Azerbaijan Airlines plane crash on Christmas Day has prompted speculation the plane was shot down by Russia after it took a detour of hundreds of miles in the wrong direction and crash-landed with holes in the fuselage.