The Bolivian Government has appealed for calm after clashes between peasant protesters and security forces over its plans to export natural gas.
Last week saw protesters setting up a roadblock
Four people died on Saturday as troops and police tried to rescue a group of more than 800 tourists, including about 40 foreigners, being held by the protesters at a roadblock near Lake Titicaca.
The peasants' leader, Felipe Quispe, described the government as murderers and vowed to continue the protests.
The peasants say the natural gas should be used to supply poor Bolivians before it is exported.
Bolivia has the largest reserves of natural gas in Latin America and is in talks with the United States and Mexico on possible exports.
It has promised an information campaign on the issue, in an attempt to defuse tensions over the issue.
Last week, indigenous Aymara Indians had blocked major roads linking the country's capital - La Paz - with other towns in Bolivia and also with neighbouring Chile and Peru.
Some demonstrators are also angered by plans to export the gas through ports in Chile which belonged to Bolivia until a war in 1879.
The government has ruled out holding a referendum on the issue.
Correspondents say that Bolivia's failure to export its gas abroad would not only starve this desperately poor country of much needed cash, it would also alienate foreign investors who have pumped about $2.5bn into Bolivia's gas projects.