LA PAZ, Bolivia (AP) — Pressure is growing at home and from abroad for Bolivia to hold a second round of voting after a disputed election that President Evo Morales says he won outright, with more protests erupting and the United Nations backing an audit of the vote amid fraud allegations.

Morales and his election rival, former president Carlos Mesa, exchanged bitter words, with Mesa accusing the president of staging "a monumental fraud" to win a fourth straight term. Bolivia's first indigenous president accused Mesa of seeking to oust him in a coup d'etat with international support.

In New York, U.N. Secretary-General Antonio Guterres said the world body supports an audit of Bolivia's election results to be done by the Organization of American States and he appealed to the sides "to keep the maximum restraint."