Thousands of people protested in the Bolivian capital, La Paz, on Friday against the controversial election result that gave President Evo Morales a fourth consecutive term.
Demonstrations were held in other cities after election authorities confirmed Mr Morales as the winner of last Sunday’s vote.
Claims of vote-rigging were made after the count was interrupted for 24 hours, but Mr Morales has denied meddling in the election. Electoral officials have also rejected accusations of fraud made by the opposition.
On Saturday, second-placed candidate Carlos Mesa rejected the result, describing it as a “fraud and breach of the popular will”.
Observers from the Organization of American States (OAS) as well the US, Brazil, Argentina and Colombia have called for a second-round vote.
In comments broadcast on state TV, Mr Morales invited ministers from those countries to carry out an audit of the votes, and vowed to hold a run-off election if any fraud was discovered.
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