The Bolivian ruling party has called on its supporters to defend President Evo Morales after police in some cities joined him in protests against him.
Demonstrators accuse Mr. Morales, the longest-serving leader in Latin America, of rigging elections last month for securing a fourth term.
On Saturday, protesters from the opposition overran two state-run media in La Paz and forced them to come out.
Mr Morales denies any wrongdoing and says he will not resign.
He also condemned the seizure. on television and radio stations, tweeting: "They [the protesters] say they defend democracy, but they act as if they were in a dictatorship."
The country's defense minister said there were no plans to deploy troops to quell the uprising.
For their part, the Bolivian armed forces have stated that they will never go against the people and that the crisis must be resolved by democratic means.
So far, three people have died and hundreds have been injured in the riots that lasted more than four weeks.
The main rival of President Carlos Mesa rejected a proposal for a dialogue ̵
What do we know about the demonstrations?
Mr Morales's Socialist Party called on its supporters to come to La Paz and "defend" the results of the controversial election. The demonstrations of the previous day, on Friday, were the first to involve a large number of police – although
Uniformed officers joined protesters in cities, including La Paz and Sucre.
Speaking to local media, several uniformed officers called for Mr Morales to resign – saying they would stop him from turning Bolivia into a dictatorship like its allies in Cuba and Venezuela.
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In a tweet, President Morales called the protests "an attack on the rule of law."
Defense Minister Javier Zaballeta, speaking to state television, called for calm and said he was confident police would "continue to carry out their constitutional work to protect people".
Earlier this week, the mayor of a small town was attacked by protesters who dragged her barefoot in the streets, covered her with red paint and forcibly cut her hair.
Why are people protesting?
Bolivia has been shaken by protests, strikes and obstacles since the country held the October 20 presidential election.
Tensions first ignited on the night of the presidential election after the number of results was inexplicably paused for 24 hours. The end result gave Mr Morales little more than the 10 percent advantage he needed to win the first round of the race immediately.
The Organization of the United States of America (OAS) is conducting a voice audit and the results are expected to be published next week.
But Mr Mesa – the second-place candidate – opposed the audit, saying his party had not been consulted.
The former president himself asked the Congress of Bolivia to pass an emergency bill to prepare for new elections.