The Economic Community of West African States (ECOWAS) Court ruled that Guinea violated the protesters' human rights, and ordered the state to pay the plaintiffs total damages of 4.56 billion Guinean francs, or $463,000. It also ordered the state to cover the costs of the litigation.

"Guinea violated the right to life, the right not to be subject to torture or to inhuman or degrading treatment, the right not to be arrested or detained arbitrarily, and the right to effective recourse," said Justice Gberi-Bé Ouattara, reading the court's ruling.

Guinea's mines minister did not immediately reply to a request for comment. Guinea had argued during the case that the state did not order the security forces to kill or torture protesters, and therefore bore no responsibility for the deaths.

On Aug. 3, 2012, Guinea sent troops and police to a site near the mining project controlled by VBG, a joint venture between Vale and billionaire Beny Steinmetz's BSG Resources (BSGR), after residents of nearby village Zogota staged a sit-in.

In the early hours of the following day security forces opened fire. Some protesters who survived were later tortured in custody.

"Everyone is rejoicing today because compensation is going to help people re-establish their lives," said Jonathan Kaufman, executive director of Ghana-based Advocates for Community Alternatives, which joined the lawsuit alongside the victims.

"What the plaintiffs and the remainder of the community have been crying out for for eight years is justice... in that sense the court gave them everything they were asking for."

Vale, the world's largest iron ore producer, denied blame for the unrest: "Vale states that it never supported any form of violence at Zogota," a spokeswoman said in a written statement when asked to comment on the court ruling.

"In 2012, the VBG encampment was invaded by protesters and its installations were damaged. For reasons of security, employees were removed in an orderly fashion, safeguarding the physical integrity of the entire team. Thereafter, VBG complied with its duty of informing the local authorities," she said.

When asked to comment, a spokesman for BSGR referred Reuters back to Vale, which operated the site at the time.

(Reporting by Helen Reid, Additional reporting by Bate Felix in Dakar, Saliou Samb in Conakry, Gram Slattery in Rio de Janeiro; Editing by Peter Graff)