Police stations in front of the presidential palace in Bolivia have given up their posts on Saturday and increased pressure on President Evo Morales after a controversial election.

The officers also climbed onto the roof of a nearby police station where Bolivian flags and signs saying "The police with the people" were attached.

The police retreated to their barracks in at least three towns, and there were reports that some in two cities openly declared mutinies.

The president, who was not in the palace at the time and later appeared in a military airfield outside of La Paz, called on the police to uphold Bolivia's "security" and abide by the rules.

Increasing disunity in the ranks of the police posed a new threat to Mr. Morales, who won the post-20 October vote, but has since been subjected to protests that killed three people and injured hundreds. Opponents claim that the results have been manipulated.

Mr. Morales is in power for the "most complicated moment" of his 14 years, and the situation could be worsening, said Jorge Dulon, a political scientist at the Catholic University of Bolivia in La Paz.

Police units in some cities began protesting on Friday and marched in uniform in the streets when anti-government protesters cheered them off the sidewalk.

Defense Minister Javier Zabaleta initially downplayed the police protests and said that in some regions there had been a "police mutiny".

General Williams Kaliman, the military chief, said the army had no plans to intervene.

"We will never confront the people we live in. We guarantee a peaceful coexistence," said General Kaliman, "this is a political problem and should be resolved in this area."

A list of demands from dissident police officers contained better working conditions, the resignation of their commander and the guarantee that they would not be used as a political "instrument of any government".

At a press conference on the military base, Mr Morales appealed to the political groups in Bolivia to hold talks. He said that the four parties that received the most votes in the nine-candidate elections should be composed of "an open agenda to pacify Bolivia."

Carlos Mesa, the main opposition leader and former president who finished second in the vote on 20 October, immediately rejected the proposal.

"I have nothing to do with Evo Morales, who is no longer in control of reality," he said.

Another opposition leader, Luis Fernando Camacho, said the president "looks for exits when people demand his resignation and call for new elections".

While calling for dialogue, Morales also accused his opponents of trying to overthrow the legitimate government of Bolivia.

The Organization of American States is conducting an audit of the election results. The results are expected on Monday or Tuesday.

The opposition, which allegedly committed electoral frauds, stated that it would not accept the findings because they had not been consulted on the audit plan.

Mr Morales ran for a fourth term after refusing to comply with the results of a referendum, which determined the term of office of the President. The country's Constitutional Court ruled that term limits violated its official title.