Oil output at Peru’s largest facility has fallen 70 percent since indigenous rights protesters occupied the site on Monday. Native communities blame foreign energy companies like the Argentinian operators of the targeted plant for dozens of crude spills in the Amazon rain forest — some on the territory of remote tribes.

Protest leader Carlos Sandi of the Achuar tribe said Thursday that the protest would continue until the government provides a solution, adding that 400 police had been dispatched to the region.

Native communities have taken control of facilities and key roads in the Amazonian region of Loreto — in northern Peru, where Argentinian energy company Pluspetrol operates an oil facility known as block 1-AB.

The field produces between 15,000 and 17,000 barrels per day. It represents about a quarter of Peru’s relatively small output. The production has dropped by about 11,000 barrels per day.

Pluspetrol’s oil facilities are located near the Corrientes River where, last year, the government declared an environmental state of emergency. Two additional environmental emergencies were declared by President Ollanta Humala in large swaths of the Amazon rain forest near the oil field after finding dangerous levels of pollution on lands used by several tribes.

“Argentinian firm Pluspetrol is currently the most intransigent company in the region,” Indigenous rights group Alianza Arkana said on its website. The group added that almost half of the 8,000 Achuar people living in 31 communities in Loreto were considered "direct victims" of scores of crude oil spills and other forms of contamination.

Pluspetrol said communities were demanding to meet with the central government to talk about public health, the environment and the distribution of oil proceeds.

“Conversations are under way to bring a solution to the impasse,” Pluspetrol said in an emailed statement. “A government commission is there and we hope this is resolved soon.”

Indigenous leaders have said neither the government nor the company have taken any concrete actions to clean up the environment or compensate affected communities.

The Environment Ministry said in a statement last week that a commission formed by government and company representatives has been assigned to work with communities to tackle pollution problems and other concerns.

Block 1-AB has been pumped for more than four decades. Pluspetrol has controlled the concession since 2001, and U.S. company Occidental Petroleum operated it before that.

Pluspetrol has also developed gas resources in the Amazon rain forest, and has additional operations on a separate indigenous reserve further south in Peru, Survival International — a natives rights group, said on its website. The facilities are located in Camisea, in the heart of the Nahua-Nanti reserve where several uncontacted tribes live.

In January, Peru’s government approved an expansion of the company's natural gas activities in Camisea — located 62 miles from Machu Picchu. Three ministers in the government resigned over the deal to expand further into indigenous territory, and the move was condemned by the United Nations.

With wire services