Finland has seized an oil tanker suspected of having severed undersea power and internet cables, with Finnish authorities saying the vessel may have been part of Russia's "shadow fleet" of ships aimed at skirting Western sanctions.

A vessel delivering oil for Russia was detained by Finland authorities on Thursday in connection with an undersea cable cutting incident that disconnected electricity to Estonia.

The Finnish authorities said the tanker might be part of Russia’s shadow fleet, which emerged as a way to circumvent Western-imposed price caps on Russian oil transported by sea. The caps were introduced several months after President Vladimir V. Putin of Russia ordered the full-scale invasion of Ukraine in February 2022.