An estimated 40,000-strong crowd paralysed the capital, La Paz, as lawmakers gather for an emergency session to debate calls for a constitutional assembly on regional autonomy.
The debate pits legislators from the right and centrist majority, mainly from eastern Bolivia, with a militant left-wing minority supported by street protesters.
Five people were injured on Wednesday in the eastern city of Santa Cruz in clashes between a youth organisation and protesting Quechua and Aymara Indians.
The youth group supports regional autonomy for Santa Cruz province, the wealthiest region of the country.
Legislature speaker Hormando Vaca Diez said Congress would meet “with or without consensus” on the burning issues of regional autonomy and a constitutional assembly.
The government has rejected the idea of international mediation, but raised no objection against discussing the issue at an Organisation of American States summit in Florida next week.
President Carlos Mesa has blamed radical groups for the unrest, saying they are conspiring to prevent Congress from meeting and trying to destabilise the country to provoke a military coup.
If Mr Mesa were to step down, Vaca Diez — who has been accused of fueling the unrest — would become Bolivia’s president.
Disagreement over exploiting Bolivia’s gas reserves resulted in deadly riots that toppled president Gonzalo Sanchez de Lozada in October 2003.
He was replaced by vice president Mesa, a popular historian and journalist with no political party to support him.
Bolivia’s gas-rich eastern provinces seek regional autonomy.
The Andean half of the country, including La Paz and the home of impoverished Quechua and Aymara Indians, demands a cut in the gas wealth and is looking for a constitutional assembly to resolve the dispute.
Protests have been held almost daily since Congress approved an energy law on May 17 giving Bolivia a greater stake in the country’s lucrative natural gas industry.
Foreign oil companies operating in Bolivia claim the legislation gives the government far too much control.
But opposition groups say the law does not go far enough and are demanding full nationalisation of oil and gas.