Jeanine Añez waves from the balcony of the Quemado Palace in La Paz after claiming Bolivia’s interim presidency. Photograph: Aizar Raldes/AFP via Getty Images

The Bolivian senator Jeanine Añez has declared herself the country’s interim president after the resignation of Evo Morales, even though lawmakers from his party boycotted the legislative session where she assumed office.

Añez, 52, took temporary control of the Senate late on Tuesday. “I will take the measures necessary to pacify the country,” she said, swearing on a bible to loud cheers and applause. The move is expected to pave the way for fresh elections.

Morales’s Movement Towards Socialism called the session illegal and its legislators refused to take part. Nearby hundreds of Morales supporters marched against Añez assuming the role. “She’s declared herself president without having a quorum in the parliament,” Julio Chipana told the Guardian. “She doesn’t represent us.”

Morales, who resigned under pressure from police and the army after a fiercely disputed election, has flown into exile in Mexico, leaving a confused power vacuum behind in Bolivia. Speaking at a hastily organised press conference on the tarmac, the former president thanked Mexico for “saving my life” and repeated his accusation that his rivals had forced him out in a coup.

He said that before his resignation on Sunday a member of the army had showed him messages putting a $50,000 price on his head.

“I thought we had finished with the discrimination and the humiliation, but new groups have emerged that have no respect for life, let alone for the fatherland,” Morales said. “It’s another lesson to learn.”

Morales, 60, was greeted with a handshake, a hug and a pat on the cheek from Mexico’s foreign minister, Marcelo Ebrard, after the flight in a Mexican army plane from the Bolivian city of Cochabamba.

He defended his time in government and said that if he were guilty any crime, it was to be indigenous and “anti-imperalist”.

Morales was accompanied by his former vice-president, Álvaro García Linera, who has been his closest political collaborator since before he became Bolivia’s first indigenous president in modern times.

“García Linera and I have always been committed to the idea that peace can only come with social justice,” Morales said. “This coup is not going to change our ideology.”

Though he promised that this was not the end of his political career, the Bolivian leader gave no indication of his immediate plans.

Morales left behind a country close to chaos as supporters and opponents clashed on the streets, amid reports of fresh looting, vandalism and arson after the October election, which the Organisation of American States found to have been rigged in his favour.

On Tuesday much of Bolivia’s main city, La Paz, was like a ghost town after police warned inhabitants to stay indoors. Roadblocks were thrown up across the city as the political uncertainty continued and residents feared more violent clashes.

The country remained in political limbo as senators and deputies loyal to the former leader appeared to refuse to endorse the new interim president, deputy senate leader Jeanine Áñez.

“The people who have been in all these protests want us to call presidential elections which are not fraudulent, which are trustworthy,” Áñez, a political opponent of Morales, told journalists in the national assembly building.

Shirley Franco, an opposition member of parliament, said: “What Bolivians want in this moment of crisis is certainty and we, the maximum authorities in this country, must work to re-establish democracy.”

Manning a makeshift barricade a few blocks away, anti-Morales protester Danella Ormachea, 29, said: “We want this to end. We need a new interim president to call new elections so there is democracy and our vote is respected. That’s all we ask.”

Martín Cornejo Choque, a rural leader in La Paz province, denied there had been voter fraud.

“Before the election, the right said if Evo Morales wins we won’t recognise it. The opposition just don’t want to recognise the votes of the rural areas,” he said.

Cornejo, who led dozens of communities to La Paz’s San Francisco square in support of Morales, said Morales had transformed life for rural Bolivians.

“Before when there were rightwing, neoliberal presidents they never cared about the peasant farmer. We lived in extreme poverty,” said Cornejo. “Our roads were not paved, we didn’t even have bridges but today, thanks to this government, all the peasant communities have development.”

Morales’s sudden departure was a dramatic fall for the former coca growers’ union leader who swept to power 14 years ago in a historic election.

He went on to win two more landslide victories and lifted millions out of poverty, but Morales’s popularity began to wane in 2016, when he ignored a referendum in which voters said he could not run for a fourth term.

Mass protests broke out after last month’s election following an unexplained 24-hour halt in the voting which fuelled accusations of electoral fraud.

Áñez denied that Morales had been the victim of a coup, saying: “What happened in Bolivia was the verification of monumental fraud. A coup d’etat is when there are soldiers in the streets.”

Neighbouring countries’ responses to the ousting of Morales have reflected the ideological divisions of a continent where populism on the right and the left has been on the rise once again.

Those backing Morales included Venezuela’s embattled leader Nicolás Maduro, Nicaragua’s seemingly eternal president Daniel Ortega, and Cuba’s Miguel Díaz-Canel.

This camp also includes Brazil’s former president Luiz Inácio Lula da Silva, who blamed it on Latin America’s “economic elite”, and Argentina’s president-elect, Alberto Fernández, who said it returned the region to “the bad days of the 70s”.

Brazil’s current far-right leader, Jair Bolsonaro, has been the loudest voice against Morales. “The left uses the word ‘coup’ a lot when it loses, right?” he told O Globo.

a tradition we should be proud of and continue,” Ebrard said on Tuesday.