Protesters in Bolivia have launched a series of strikes and set up roadblocks across the country to show their opposition to government plans to export natural gas.
Protesters threaten to cut-off supplies to the capital
The protesters - most of them indigenous Aymara Indians - are blocking major roads linking the country's capital, La Paz, with other towns in Bolivia and also with neighbouring Chile and Peru.
They are demanding that some 250,000 homes in Bolivia be supplied with gas for free before any of it is exported.
Bolivia has the largest natural gas reserves in Latin America and is currently negotiating sales contracts with the United States and Mexico.
But the BBC's Elliot Gotkine says that Bolivia's failure to export its gas abroad would not only starve this desperately country of much needed cash - it would also alienate foreign investors who have pumped about $2.5 billion into Bolivia's gas projects.
Our correspondent says that Bolivia's latest descent into social unrest came as little surprise.
Bolivian troops have been sent to guard major roads
Last week, thousands of protesters marched for seven days to the country's highland capital to declare war on a host of government policies.
They demand talks with the government over the controversy, and have prepared a 70-point document addressing different issues.
Bolivia's main opposition leader Evo Morales has threatened to launch a series of nationwide strikes on Friday, if the government of president Gonzalo Sanchez de Lozada refuses to meet the demands.
Some of the protesters are particular angry at the government's plans to use Chilean ports on the Pacific coast for exporting the gas, because the ports belonged to Bolivia before the 1879 war with Chile.