LIMA (Reuters) - Indigenous groups in Peru are turning to the courts with a new legal strategy for keeping mining and oil projects off their lands, racking up victories that could make it harder for companies to secure permits in the Andean country, a major minerals producer.

Slideshow ( 7 images )

Native communities from the Peruvian Amazon and the Andes have filed at least eight lawsuits against the government since passage of the “prior consultation” law in 2011, which gives them the right to weigh in on official decisions that could affect their communities, according to judicial documents.

The law, based on an international pact Peru signed in 1993, aimed to grant overdue rights to indigenous people and prevent deadly clashes over mining and energy projects.

But several indigenous communities complained the government did not consult them, or when they did, did not consult them early enough, on plans for tapping nearby oil or mineral reserves.

So far, the courts have agreed with the indigenous.

Judges sided with native communities in all six of the lawsuits that have been decided since the 2011 law’s passage, pointing to international law to annul the government’s greenlighting of projects, including mining and oil concessions.

“Without a doubt, an important precedent is being set with these cases,” said Jose de Echave, a director of the local environmental group Cooperaccion.

For mining and oil companies, that might mean an added wait while the government discusses potential extractive activities with indigenous groups. While communities cannot unilaterally block a project under the prior consultation law, the government must try to reach some agreement.

The two pending lawsuits include requests to suspend Glencore’s proposed $590 million expansion of its Antapaccay copper mine and Chile-based GeoPark’s plans to drill for oil in the Amazon region.

Glencore and GeoPark both declined to comment on the lawsuits.

Peru’s energy and mines ministry also declined to comment.

“We’re the owners of this land. We’ve lived here before the state was formed,” said Sumbinianch Mitiap, a representative of the indigenous Achuar community that is opposed to GeoPark’s drilling plans.

The lawsuit the Achuar filed is just one tool they are using in hopes of blocking GeoPark from drilling for oil on their land. On Thursday, members of the community held a protest outside the company’s headquarters in Santiago and met with its shareholders to push for a withdrawal from its Peru project.

The mining permits revoked so far - 200 concessions for exploration in the Amazon - were relatively minor, far from the big deposits in the Andes that have made Peru the world’s No. 2 copper, zinc and silver producer.

But with 31,000 mining concessions issued in the past two decades according to Cooperaccion, the legal precedents the cases set are potentially huge - exciting indigenous rights activists, but alarming industry.

“We’re watching the recent judicial rulings with deep worry,” said Pablo de la Flor, the executive director of Peru’s National Society of Mining, Petroleum and Energy.