The United States authorized non-emergency U.S. officials to leave on Bolivia Tuesday, citing "ongoing political instability" in the nation. The announcement came as clashes broke out in the streets in response to an opposition leader in the Senate declaring herself Bolivia's interim president.

"The U.S. government has limited ability to provide emergency services to U.S. citizens in Bolivia," the State Department said in a statement. "There are recurring demonstrations, strikes, roadblocks, and marches in major cities." The statement ordered family members of government employees to leave the nation.

On Monday, ousted leader Evo Morales fled the country for Mexico. Morales stepped down Sunday under pressure from Bolivia's military following weeks of violent protests fed by allegations of electoral fraud in the Oct. 20 presidential election that he claimed to have won. Resignations by every other constitutionally designated successor left unclear who would take his place and how.

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Morales posted a photo of his first night after he resigned showing him lying on a floor with an improvised blanket as a bed. He said had been forced into these conditions after what he has called a coup by the opposition.

Supporters of Bolivian President Evo Morales and opposition supporters clash during a protest after Morales announced his resignation on Sunday, in La Paz Bolivia November 11, 2019. REUTERS

Angry supporters of the socialist leader set barricades ablaze to close some roads leading to the country's main airport Monday, while his foes blocked most of the streets leading to the capital's main square in front of Congress and the presidential palace. Police urged residents of La Paz to stay in their homes and authorities said the army would join in policing efforts to avoid an escalation of violence.

Jeanine Añez, the Senate's second vice president, claimed the post of Senate leader late Tuesday, even though she lacked a quorum because of a boycott by Morales' Movement for Socialism party. The position is next in line for the presidency. Without being sworn in by anyone, she then appeared on a balcony of the old presidential palace wearing the presidential sash and holding a Bible in her hand.

"My commitment is to return democracy and tranquility to the country," she said. "They can never again steal our vote."

It was uncertain how much support Añez could count on from other power centers in her bid to replace Morales. Some Bolivians quickly took to the streets cheering and waving national flags in opposition strongholds like the cities of Santa Cruz and Cochabamba, but angry Morales' supporters tried to reach the Congress building in La Paz screaming, "She must quit!" Police and soldiers fired tear gas trying to disperse the crowd and detained some demonstrators.

A police officer detains an injured man during clashes between supporters of Bolivian President Evo Morales, who announced his resignation on Sunday, and opposition supporters in La Paz, Bolivia, November 11, 2019. REUTERS

Morales said on Twitter from Mexico that Añez's "self-proclamation" was an affront to constitutional government. "Bolivia is suffering an assault on the power of the people," he wrote.

Even before Añez acted, thousands of his supporters were in the streets of the capital in peaceful demonstrations clamoring for his return. Military fighter jets flew repeatedly over La Paz in a show of force that infuriated Morales loyalists who were blocked by police and soldiers from marching to the main square.

Morales ran for a fourth term after refusing to accept the results of a referendum that upheld term limits for the president — restrictions thrown out by a top court that critics contend was stacked in his favor.

"The whole population was tired of him because it's been nearly 14 years of government," said a businessman from the city of Cochabamba, who asked to be identified only by the name Walter, fearing reprisals by Morales supporters.

"There was no respect anymore. We're hurt. He believed himself to be a god."