La Paz — The Bolivian Miners Federation increased its pressure on the government. The miners backed farm laborers, who late last week blockaded all major roads into La Paz, the capital. The laborers' union, protesting low farm prices and the lack of development in rural areas, then threatened to extend the blockade if its demands were not met. The government has agreed to see union representatives. Earlier this month, the miners took over the country's state-owned tin mines. It is not the first time the powerful federation has occupied the mines as a way of pressuring the nation's leaders.