Greenpeace activists have stormed a floating oil rig in Russia’s Pechora Sea, hundreds of miles (kilometers) from the nearest port, to protest oil drilling in the Arctic, the environmental organization said Friday.

The six activists boarded the Prirazlomnaya platform early Friday and remain on the rig, Greenpeace said in a statement. They set off in inflatable speedboats from their ship and scaled the platform with mooring lines.

The activists, who include Greenpeace’s chief Kumi Naidoo, did not face much resistance from oil workers and managed to put a banner on the rig saying “Don’t kill the Arctic.”

“We’re here peacefully and we will continue to draw the attention of Russian people and people around the world to what’s happening there,” Naidoo told The Associated Press by telephone from the platform. “It’s bad for Russia, it’s bad for the planet.”

Prirazlomnaya is owned and operated by a subsidiary of Russian energy giant Gazprom, which is pioneering Russia’s oil drilling in the Arctic. The state-owned company installed the drilling platform there last year and is preparing to drill the first well.

Naidoo, a South African, told the AP that the activists are suspended from the platform’s mooring lines. He said many of the platform’s employees “have been very friendly, engaging in conversations with us, asking where we come from and offering us soup.”

Naidoo said the activists have been told by one of the platform employees that a Russian coast guard helicopter is on its way to detain them. He said the five activists with him include two from Germany, and one each from the United States, Canada and Finland.

The platform is about 620 miles (1,000 kilometers) from the nearest port — Murmansk, a city on the extreme northwestern edge of the Russian mainland.

Gazprom told the AP in an emailed statement that the activists “have been invited to scale up to the platform for a constructive dialogue,” but said that they refused. The company said that “all work on the platform proceeds as normal.”

Greenpeace said that its activists have supplies to last “for an extended stay.”

Russian and international environmentalists have warned that drilling in the Russian Arctic could have disastrous consequences because of a lack of technology and infrastructure to deal with a possible spill in a remote region with massive icebergs and heavy storms.

An AP investigation last year found that at least 1 percent of Russia’s annual oil production, or 5 million tons, is spilled every year.

A report by Greenpeace and World Wildlife Fund, issued last week, said that a spill from Prirazlomnaya could contaminate protected areas and nature reserves on the shore and islands within 20 hours, while emergency teams would take at least three days to reach the area.