TOHONO O'ODHAM RESERVATION - The Federal Bureau of Investigation has opened an investigation after two Border Patrol agents shot and wounded two suspected drug smugglers after, agents say, the pair threw rocks at them. The FBI's Manuel Johnson says the violence occurred Saturday afternoon on the Tohono O'odham Indian Reservation about 40 miles west of Nogales. Johnson says border agents intercepted two men hauling backpacks containing drugs. The agents opened fire after the suspects hurled rocks at them.