Soldiers fired on a bus with miners heading to demonstrations in Sucre on Thursday, Interior Minister Saul Lara told reporters. Two more miners were wounded, Lara added.
The death was the first in nearly four weeks of protests by an impoverished indigenous Indian majority that have triggered the worst turmoil in Carlos Mesa's 19 months in government.
Police also fired tear gas at peasants and students who set off sticks of dynamite and fireworks in the streets to protest against Mesa's possible replacement, Senate President Hormando Vaca Diez.
Many demonstrators demanded Vaca Diez step aside to allow Bolivians to go to the ballot box, even though the constitution calls for the wealthy rancher to assume the presidency.
Analysts say Vaca Diez is seen by many Bolivians as representing a failed traditional, political class.
But he appears to have the support of his MIR party and the MNR, the largest bloc in the 157-member legislature.
Bolivia's military commanders urged for calm and warned demonstrators they would support whatever Congress decided.
"We will respect the Congress' decision ... as long as there is no break with the constitution and no break with democracy, the armed forces will remain the supervisors of this process," Armed Forces Commander-in-Chief Admiral Luis Aranda
said. "We are at maximum alert."
Indian groups say Bolivia's energy riches have benefited only the white, European-descended elite. They want an assembly on constitutional reform to give them more representation.
Bolivia has witnessed social and
political upheaval recently
The last president, Mesa, resigned after three weeks of blockades by Indian groups calling for total state control over energy reserves and a special assembly to grant them more power.
Protests have caused fuel and food shortages in La Paz and stoked fears of violence in South America's poorest nation.
Several airlines have suspended flights and the United States ordered non-emergency personnel to leave its embassy.
Spain has also sent an Air Force plane to neighbouring Peru on Thursday in case it needed to evacuate Spanish citizens from Bolivia.