Russia has charged 14 Greenpeace activists with piracy after they protested at a Russian oil platform and two tried to board it.
The activists could face up to 15 years in prison if convicted of piracy.
The individuals from Britain, Argentina, Brazil, Finland, the Netherlands, Poland, Russia and Sweden were among 30 people from 18 countries who were on the Greenpeace ship seized by the Russian Coast Guard last month.
Two of them tried to scale an offshore platform owned by Russian state-controlled energy giant Gazprom to call attention to the environmental risks of drilling in Arctic waters.
More were expected to be formally charged today and tomorrow, Greenpeace said.
All 30 activists were being held in jails in Murmansk, north of the Arctic Circle.
President Vladimir Putin said last week that he does not think the activists are pirates, which triggered hopes for their release.
But prime minister Dmitry Medvedev urged energy companies to adopt better security.
He said the government should consider tougher penalties for those who attack or trespass on Russian oil and gas rigs.
“Concern for the environment must not cover up unlawful actions, whatever lofty goals the people who were taking part in them espoused,” he said.
The platform, which belongs to Gazprom’s oil subsidiary, is the first offshore rig in the Arctic.
It was deployed to the vast Prirazlomnoye oil field in the Pechora Sea in 2011, but its launch has been delayed by technological challenges.
Gazprom said in September that it was to start pumping oil this year, but no date has been set.
Russian investigators said that the Greenpeace ship, the Arctic Sunrise, had violated the 500-yard security zone around the platform and that it was carrying equipment whose purpose was still unclear. Greenpeace has insisted that its ship stayed out of this zone and that the inflatable boats used by activists to reach the platform posed no danger.