Greenpeace said on Saturday it had defied the Russian authorities by sending its icebreaker through an Arctic shipping route to protest against oil drilling in the fragile ecosystem.
Earlier this week the global environmental group said Russia had refused its ship permission to enter the Northern Sea Route on several occasions citing concerns about the icebreaker's ability to withstand thick ice.
Greenpeace has called the move "a thinly veiled attempt to stifle peaceful protest."
In defiance of the Russian authorities, the Greenpeace ship Arctic Sunrise entered the Northern Sea Route early Saturday morning to protest plans by the country's top oil firm Rosneft and its US partner ExxonMobil to drill near the Russian Arctic National Park, the group said.
"We refuse to let illegal attempts by the Russian government to stop us from exposing dangerous oil drilling in the Arctic.
"The Russian Arctic National Park is a special place full of rare and threatened Arctic wildlife, and faces an infinitely greater threat from reckless oil companies than a fully equipped Greenpeace icebreaker," Christy Ferguson, Greenpeace Arctic Campaigner aboard the Arctic Sunrise, was quoted as saying.
"If Rosneft and ExxonMobil bring in offshore drilling platforms they will risk catastrophic blowouts and spills that could devastate the region," said Ferguson, adding the two oil majors "rely on secrecy and evasion."
Greenpeace said the plans to drill in the protected ecosystem were in contravention of Russia's own environmental laws.
Rosneft, headed by one of Putin's closest confidants, Igor Sechin, did not immediately react.
Both Russia and the United States hope that the global warming gradually melting the Arctic sea ice will help them tap the vast oil and natural gas resources believed to be buried in the region.
Putin has pledged to turn the Northern Sea Route into a key shipping artery, part of the Kremlin's bid to mark out its stake over the energy-rich Arctic.
Explore further: 3Qs: Game theory and global climate talks