RIO DE JANEIRO • Brazil stripped a vast Amazon nature reserve of its protected status in a move that could expand mining in the region, in a decree published this week.

The 47,000 sq km Copper National Reserve, about the size of Switzerland, is rich in minerals like gold, zinc, phosphate and manganese.

Established in 1984 under the then military dictatorship, the reserve's protected status restricted mining activities to state companies.

Wednesday's decree stressed that it does not override other existing environmental protection laws.

However, campaign groups such as the World Wide Fund for Nature have expressed concern about the environmental threat to the reserve from potential mining projects.

Mining at the reserve could also exacerbate existing conflicts between mining companies and indigenous groups, say environmental activists.

The park includes nine protected zones, two of which are indigenous lands where mining is completely banned, but at least four other zones appear to be accessible to regulated mining activity.

A report by the mining ministry in April said that lifting the protected status could provide "access to minerals potentially existing in the region", by letting private companies operate there.

The mining department in Amapa, one of the states that are home to the reserve, said environmental institutions were supervising the plans.

AGENCE FRANCE-PRESSE, XINHUA