Street battles broke out on Monday between supporters of President Evo Morales and opposition leader Carlos Mesa as protests against alleged electoral fraud in Bolivia entered a second week.
Residents of the Achumani neighborhood in southern La Paz used branches, rubble and rope to close roads and block access to public transport, with some bus drivers trying to remove the barricades.
Fist fights broke out between rival groups, which then degenerated into battles with sticks and stones as police used tear gas to try to disperse them.
Regime and opposition figures blamed each other for the violence.
Demonstrations have raged since presidential elections on Oct 20 that saw Morales gain an unconstitutional fourth term amid allegations of irregularities in the vote count.
Mesa, who accused the government of fraud, has urged his supporters to keep up the pressure with strikes backed up by street protests.
The government is entirely responsible for the violent actions, Mesa wrote on his Facebook page.
Vice President Alvaro Garcia Linera blamed Mesa for the clashes, calling him angry, liar and deceitful. He is responsible, he is guilty, said Garcia Linera.
La Paz mayor Luis Revilla, a Mesa ally, told reporters the opposition strike was peaceful but said pro-Morales shock groups were provoking confrontations around the country.
In the central city of Cochabamba, clashes broke out between opposition supporters setting up barricades and regime loyalists trying to break them up.
No injuries were reported either in La Paz or Cochabamba.
La Paz's business district, where government offices are located, was relatively calm. But there were road blocks in many other neighborhoods.
A general strike paralyzed Santa Cruz in the east and the mining city of Potosi in the southeast. On Sunday, Morales claimed the opposition was preparing for a coup d'etat.
At the centre of the conflict was a sudden and unexplained change in the ballot count last Monday that boosted Morales's lead, pushing him over the 10-point margin of victory required to avoid a run-off.
Mesa has denounced the official results while various foreign powers, including the European Union and United States, have called for a run-off.
The Organization of American States (OAS), voicing surprise and concern over the ballot count, has agreed to conduct an audit of the results.