Russian authorities say Greenpeace activists arrested after protesting against exploratory oil operations in the Arctic will probably be charged with piracy.
The campaigners’ ship was taken to Murmansk after Russian coastguard officers boarded it and detained the 30 crew members.
Greenpeace sent its ship the Arctic Sunrise to the platform in the Pechora Sea, 60 kilometres from Russia’s northern coast.
Two activists, thought to be Finnish and Swiss nationals, tried to scale it. The Russian Foreign Ministry initially described their action as aggressive and provocative.
Greenpeace argues that seismic tests are dangerous for animals such as whales and dolphins.
The environmentalists denounced the Russian response as heavy-handed, accusing special forces of pointing guns at them and slashing their rubber dinghies.
The authorities say the activists will be prosecuted regardless of nationality.
Piracy carries a potential 15-year jail term in Russia.