The protesters marched on San Francisco Square, where scores of heavily armed police and soldiers had blocked streets near Congress, demanding "justice" and the resignation of interim president Jeanine Anez.
If he had stood down at the end of his term in January, he would have reaped goodwill for his achievements, hailed as a champion of democratic certitudes.
The headquarters of the state Bolivia TV and Patria Nueva radio station in La Paz were also blockaded until employees were able to leave while protesters chanted "without violence".
