Soldiers have arrested an opposition governor on charges of organizing a massacre in Bolivia, the country's president said Tuesday.

Gov. Leopoldo Fernandez of Pando province was being charged with genocide in what President Evo Morales calls an ambush of his supporters last week that left at least 15 dead and 37 injured.

Anti-Morales activists seized buildings last week in Pando and three other states to protest a planned vote on a new constitution granting greater power to Bolivia's poor indigenous majority.