By Daniel Ramos

LA PAZ (Reuters) -Bolivian armed forces pulled back from the presidential palace in La Paz on Wednesday evening and a general was arrested after President Luis Arce slammed a "coup" attempt against the government and called for international support.

Earlier in the day, military units led by General Juan Jose Zuniga, recently stripped of his military command, had gathered in the central Plaza Murillo square, home to the presidential palace and Congress. A Reuters witness saw an armored vehicle ram a door of the presidential palace and soldiers rush in.

"Today the country is facing an attempted coup d'état. Today the country faces once again interests so that democracy in Bolivia is cut short," Arce said in comments from the presidential palace, with armed soldiers outside.

"The Bolivian people are summoned today. We need the Bolivian people to organize and mobilize against the coup d'état in favor of democracy."

A few hours later, a Reuters witness saw soldiers withdraw from the square and police take control of the plaza. Bolivian authorities arrested Zuniga and took him away, though their destination was unclear.

Inside the presidential palace, Arce swore in José Wilson Sanchez as the military commander, Zuniga's former role. He called for calm and order to be restored.

"I order that all personnel mobilized on the streets return to their units," Sanchez said. "We entreat that the blood of our soldiers not be spilled."

The United States said it was closely monitoring the situation and urged calm and restraint.

Tensions have been building in Bolivia ahead of general elections in 2025, with leftist ex-President Evo Morales planning to run against former ally Arce, creating a major rift in the ruling socialist party and wider political uncertainty.

Many do not want a return of Morales, who governed from 2006-2019 when he was ousted amid widespread protests and replaced by an interim conservative government. Arce then won election in 2020.

Zuniga said recently that Morales should not be able to return as president and threatened to block him if he attempted to, which led Arce to remove Zuniga from his post.

Ahead of the attack on the presidential palace, Zuniga had addressed reporters in the square and cited growing anger in the landlocked country, which has been battling an economic slump with depleted central bank reserves and pressure on the boliviano currency as gas exports have dried up.

"The three chiefs of the armed forces have come to express our dismay," Zuniga told a local TV station, calling for a new cabinet of ministers.

"Stop destroying, stop impoverishing our country, stop humiliating our army," he said in full uniform, flanked by soldiers, insisting the action being taken was supported by the public.

Zuniga told reporters later on Wednesday that Arce had on Sunday asked him to "raise something up" to boost his popularity, without offering evidence.

Interior Minister Eduardo del Castillo later said Zuniga was seeking to court popular support and that the nine people injured in the attempt proved "this was not a drill."

'STRONGEST CONDEMNATION'

Morales, head of the ruling MAS socialist party, said that his supporters would mobilize in support of democracy.

"We will not allow the armed forces to violate democracy and intimidate people," Morales said.

Bolivia's public prosecutor's office said it would launch a criminal investigation against Zuniga and others involved in the attempted coup.

Public support for Arce and Bolivia's democracy has poured in from regional leaders and beyond.

"We express the strongest condemnation of the attempted coup d'état in Bolivia. Our total support and support for President Luis Alberto Arce Catacora," Mexican President Andres Manuel Lopez Obrador said on X.

Even conservative political opponents of the government in Bolivia condemned the military action, including ex-President Jeanine Anez, who was imprisoned in 2022 amid political turmoil.

"I fully reject of the mobilization of the military in the Plaza Murillo attempting to destroy constitutional order," she wrote on X. "The MAS with Arce and Evo must be got out through the vote in 2025. We Bolivians will defend democracy."