sentences:  In 2009, Viet Tan has been very vocal about the planned bauxite mining in the central area of Tây Nguyên.Under an agreement between the Chinese government and the Vietnamese Prime Minister Nguyễn Tấn Dũng, Chinese companies were allowed access to the central highlands of Tây Nguyên for bauxite mining.Environmental concerns about bauxite mining sparked widespread international opposition among scientists, intellectuals and former soldiers.