The Group of Seven democracies have sought to crimp Russia's oil export earnings that help fund the war against Ukraine. Here are things to know about the shadow fleet — and why it worries Western governments and environmental groups.

Finland says a ship affiliated with Russia's "shadow fleet" is linked to a 60-mile-long anchor drag mark on the seafloor. A power cable in the Baltic Sea was severed last week.

The White House has announced new sanctions against Russian oil companies, aimed at causing Russia losses of billions of dollars monthly. The restrictions include Gazprom Neft and Surgutneftegaz, as well as 183 ships associated with oil exports.