Renewed clashes rocked Bolivia’s capital Wednesday as the woman who claimed the presidency, a second-tier lawmaker thrust into the post because of a power vacuum, faced challenges to her leadership from supporters of the ousted Evo Morales. A day after Jeanine Añez assumed power, violent clashes broke out between rock-throwing Morales’ backers and police in riot gear, who fired volleys of tear gas to disperse the large crowd of protesters as fighter jets flew low overhead in a show of force. Opposition was also building in Congress, where lawmakers loyal to Morales were mounting a challenge to Añez’s legitimacy by trying to hold new sessions that would undermine her claim to the presidency. The sessions — dismissed as invalid by Añez’s faction — added to the political uncertainty following the resignation of Morales, the nation’s first indigenous leader, after nearly 14 years in power. In the streets, angry demonstrators tore off corrugated sheets of metal and wooden planks from construction sites to use as weapons, and some set off sticks of dynamite. Many along flooded the streets of the capital and its sister city of El Alto, a Morales stronghold, waving the multicolored indigenous flag and chanting, “Now, civil war!” “We don’t want any dictators. This lady has stepped on us — that’s why we’re so mad,” said Paulina Luchampe. “We’re going to fight with our brothers and sisters until Evo Morales is back. We ask for his return. He needs to put the house in order.” The 60-year-old Morales, who arrived in Mexico on Tuesday under a grant of asylum, has vowed to remain active in politics and said he would be willing to go back home. “If the people ask me, we are willing to return,” he said at news conference Wednesday in Mexico City. According to the constitution, an interim president has 90 days to organize an election, and the disputed accession of Añez, who until Tuesday was second vice president of the Senate, was an example of the long list of obstacles she faces. Morales’ backers, who hold a two-thirds majority in Congress, boycotted the session she called Tuesday night to formalize her claim to the presidency, preventing a quorum. She claimed power anyway, saying the constitution did not specifically require congressional approval. “My commitment is to return democracy and tranquility to the country,” she said. “They can never again steal our vote.” Bolivia’s top constitutional court issued a statement late Tuesday laying out the legal justification for Añez taking the presidency — without mentioning her by name. But other legal experts challenged the legal technicalities that led to her claim, saying at least some of the steps required Congress to meet. The lingering questions could affect her ability to govern. Eduardo Gamarra, a Bolivian political scientist at Florida International University, said the constitution clearly states that Añez didn’t need a congressional vote to assume the presidency. Even so, “the next two months are going to be extraordinarily difficult for President Añez,” he said. “It doesn’t seem likely” that Morales’ party will accept Añez as president, said Jennifer Cyr, an associate professor of political science and Latin American studies at the University of Arizona. “So the question of what happens next remains — still quite unclear and extremely worrying.” She will need to form a new electoral court, find non-partisan staff for the electoral tribunal and get Congress, which is controlled by Morales’ Movement for Socialism Party, to vote on a new election.