Hundreds of demonstrators blocked a major highway in northern Peru this week, demanding that the largest gold mine in Latin America be shut down because it was contaminating local water supplies with mercury. Peru’s energy and mines minister, Jaime Quijandria, said it was “simply and totally impossible” for the water to have been contaminated by the Yanacocha Mine, which is controlled by the U.S.-based Newmont Mining Corp. Quijandria added, however, that he would ask local authorities to look into the matter and would issue sanctions against the mine if the pollution claim turned out to be true.