Bolivians opposed to the referendum on autonomy that the Santa Cruz provincial government and civic groups are holding, chase after tear gas grenades launched at them by police to stop them from clashing with referendum supporters, in Santa Cruz May 4, 2008. Bolivia's richest region of Santa Cruz went ahead with a vote on greater autonomy from the central government on Sunday in a referendum that President Evo Morales declared illegal, but still poses the biggest challenge yet for his government. REUTERS/Andres Stapff (BOLIVIA)
REUTERS/ANDRES STAPFF