By CARLA SALAZAR and FRANK BAJAKLIMA, Peru (AP) â¿¿ Peru's government declared an environmental state of emergency on Monday in a remote Amazon jungle region it says has been affected by years of contamination at the country's most productive oil fields, which are currently operated by Argentina-based Pluspetrol. Indigenous groups in the Pastaza River basin near the Ecuador border have been complaining for years about the pollution and the failure of successive governments to address it. Authorities say one reason the pollution was never addressed is that until now Peru lacked the requisite environmental quality standards. In declaring the emergency, Peru's Environment Ministry said the contamination included high levels of lead, barium and chromium as well as petroleum-related compounds. The region is inhabited mostly by the Quichua and Ashuar, who are primarily hunter-gatherers. The fields have been operated for roughly 12 years by Pluspetrol, the country's biggest oil and natural gas producer, and it will be obliged to clean up the contamination, said Environment Minister Manuel Pulgar-Vidal. The government also said the field's previous operator, Occidental Petroleum, had not adequately remediated contamination either. It began drilling there in 1971. Pluspetrol took over in 2001. The 90-day emergency orders immediate action to reduce the risk of contamination to the local population. It follows an $11 million fine levied against Pluspetrol in January. "We know that there has been bad environmental behavior by the company," Pulgar-Vidal said of Pluspetrol in a radio interview. "If indeed at some point remediation was done, it was not done adequately and that includes inadequate action by the authorities from 2003-2005." Pluspetrol did not immediately respond to telephone calls and email messages requesting comment. Pulgar-Vidal did not describe the extent of the contamination or estimate what it would cost to clean up. His ministry said in a statement posted on its website that the government began administrative actions against Pluspetrol in March 2012 over contamination at block 1AB, long Peru's biggest crude oil field.