Four activists last week joined Greenpeace International's Executive Director Kumi Naidoo in occupying the Prirazlomnoye oil rig in the Pechora Sea.
Greenpeace campaigners left the platform, operated by Russian energy company Gazprom, Friday and staged a similar protest Monday against a supply ship for the rig.
Russia's state-run news agency RIA Novosti cites the company's Russian division as saying the "five-day action has ended but the battle for the arctic continues."
Greenpeace said its campaign against Gazprom isn't a public relations stunt but about "stopping the destruction of the planet."
The Russian report adds that international oil companies like Exxon Mobil, Statoil and Total have signed arctic exploration agreements in recent years. Gazprom aims to start oil production in the region by early next year.
Melting arctic sea ice is exposing areas believed to hold deposits of oil and natural gas. Gazprom said it was paying "special attention" to safety issues as it looks to tap into the estimated 527 million barrels of reserves in the region.