The environmental group says rallies are scheduled across the world, including events Saturday night in Toronto and Montreal, along with protests in Port Colborne, Ont., and Wolfsville, N.S.
The crew of the seized Greenpeace ship Arctic Sunrise includes Alexandre Paul of Montreal and Paul Ruzycki of Port Colborne, and the charge they both face can result in a 15-year prison term upon conviction.
Greenpeace denies any wrongdoing and describes the charges as absurd, while Paul's mother says they make no sense.
Greenpeace International's director Kumi Naidoo says Russia's seizure of the ship and the arrest of its crew is the worst "assault" on the group's environmental activism since its flagship Rainbow Warrior ship was bombed in 1985.
Several hundred people gathered Saturday in London to protest Russia's actions, while there were smaller protests in several other British cities and in other parts of the world, including Brazil.
Russia seized Arctic Sunrise after a Sept. 18 protest at a Gazprom oil drilling platform located in the Arctic circle, and last week charged all 30 people on board with piracy.
— With files from the Associated Press.
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