LA PAZ, Bolivia — Former President Evo Morales on Monday encouraged resistance to efforts to form a transitional government leading to fresh elections in Bolivia after his resignation prompted violent protests by many of his supporters.
“You never abandoned me and I will never abandon you,” Mr. Morales wrote on Twitter from an unknown location only hours after he was forced to step down. “The world and patriotic Bolivians will repudiate this coup.”
Almost simultaneously, a leading opposition politician who has emerged as a possible interim leader of the country said she was ready to take the reins of power until new elections could be held.
The politician, Jeanine Añez Chavez, the Senate’s second vice president, appeared on television Monday morning before boarding a plane for La Paz, sobbing as she described the chaos of the night before. “Bolivia doesn’t deserve this, all these deaths and destruction,” she said, before promising a quick transition “that is absolutely necessary to return to a democracy.”
A former news executive and leader of a conservative coalition, Ms. Añez appears to be next in line for the presidency, since several more senior politicians resigned over the weekend. The national legislative assembly is expected to accept the resignations of Mr. Morales and his vice president, after which Ms. Añez may become the transitional president.
But the scramble has just begun to fill the power vacuum that followed the resignation of Mr. Morales on Sunday.
The whereabouts of Mr. Morales were unknown, though late Sunday he said on Twitter that the police were seeking to arrest him “illegally” and that “violent groups” had assaulted his home.
A video circulating on social media showed dozens of people exploring what was reported to be Mr. Morales’s ransacked home, with furniture toppled, items broken and political slogans spray painted on walls in red.
Ms. Añez, a senator from the opposition Democratic Union party, said on Sunday that she would assume the interim presidency and call a session of the legislative assembly on Monday.
“I assume this challenge with the only objective to call new elections,” she said. “This is simply a transitional phase.”
But she would need a quorum in the assembly to approve a transfer of power, and Mr. Morales’s party, the Movement for Socialism, controls both houses. His supporters in the assembly may try to block the appointment of an interim president using procedural rules, leaving a vacuum at the top of the government.
Carlos Mesa, a former president who was the losing candidate in the recent presidential election — widely considered fraudulent — said members of the opposition were attempting to appeal to the patriotism of lawmakers who have backed Mr. Morales.
“They have no reason to believe they will be persecuted,” Mr. Mesa said at a news conference Monday morning.
The scene in La Paz was chaotic. On the city’s streets, through a driving rain, the police withdrew as crowds welcomed the transfer of power with fireworks, while others looted stores and set what appeared to be politically motivated fires.
In Cochabamba, in the center of Bolivia, some businesspeople set up vigilante patrols to protect their businesses. Bands of motorcyclists came into the city from the outskirts, violently confronting people who were celebrating in the streets.
Drinking water was cut off to parts of La Paz and the adjacent city of El Alto, Bolivia’s second-largest, but the reason for the cutoff was not known.
There was little to no violence in Santa Cruz, a center of the opposition. A festival-like mood prevailed there, with people celebrating on the streets and waving flags.
The political crisis began when Mr. Morales, a leftist who came to power more than a decade ago and was once widely popular, claimed victory in the Oct. 20 election, which protesters and international observers suspected was rigged. In 2016, a court packed with loyalists allowed him to do away with the constitution’s two-term limit, allowing him to run for office indefinitely.
For weeks after the disputed election results, demonstrations paralyzed much of the country, and groups supporting the president have roughed up protesters.
But Friday night, some police units broke from the government and joined the protesters. On Sunday, the rebellion spread to the military, with the commander of Bolivia’s armed forces, Gen. Williams Kaliman, calling for Mr. Morales to step down.
Marcelo Ebrard, Mexico’s foreign minister, said on Sunday that the country would offer Mr. Morales asylum if he sought it.
Clifford Krauss reported from La Paz, and Daniel Victor from Hong Kong.