Strong performance also came on the back of strategic initiatives, such as non-core asset sales, aggressive cost control measures and a disciplined approach in reducing debt.
The 60-day decree affects 11 districts in the Madre de Dios region, where several studies have found high levels of the toxic element in people, rivers and fish.
Diamond miners have found the remains of a Portuguese ship that disappeared on its way to India laden with gold and other treasure, almost 500 years ago.