Evo Morales left Bolivia on Monday for Mexico, which has granted him political asylum, as the armed forces agreed to help police curb violence that has erupted after the president's stunning resignation left a power vacuum.
The senator set to succeed Morales as interim president, Jeanine Anez, pledged to call fresh elections to end the political crisis.
The United Nations and the Organization of American States (OAS) earlier voiced fears of a breakdown in security in a country that appeared increasingly rudderless after dozens of officials and ministers resigned along with Morales, some seeking refuge in foreign embassies.
Morales called Mexico's Foreign Minister Marcelo Ebrard on Monday to request asylum and later tweeted that he was "heading to Mexico".
Ebrard confirmed Morales had been granted asylum and late on Monday wrote on Twitter that a Mexican military plane carrying the former president had "already taken off... with Morales aboard".
"According to international conventions, he's under Mexico's protection. His life and integrity have been saved," Ebrard said.
Morales thanked Mexico for protecting him and vowed to come back to his country "stronger and more energetically".
The dramatic events came a day after Morales's shock resignation after he lost the backing of the military following three weeks of street protests over his disputed re-election for an unconstitutional fourth term.
"The military command of the armed forces has arranged for joint operations with the police to prevent bloodshed and fighting amongst the Bolivian family," said General Williams Kaliman in a televised address.
Three people have died in clashes since the disputed election.
Earlier, La Paz police chief Jose Barrenechea called on Kaliman to "intervene, because the Bolivian police have been overrun". Some small police barracks around the country were torched or looted on Monday.
"We are going to call elections," Anez told reporters in La Paz, the seat of government, saying that there will be "an electoral process that reflects the will of all Bolivians".
Morales claimed on Twitter late on Monday that two of his homes had been attacked by "vandalism groups".
That came after AFP reporters said hundreds of Morales supporters were marching on La Paz from its satellite town El Alto as opposition leader Carlos Mesa claimed on Twitter that "a violent mob" was heading for his home to attack it.
Soon afterward came the police's plea for military help.
AFP photographers saw civilians making arrests after tussling with Morales supporters in La Paz, sometimes assisted by police. Some of those arrested were made to kneel in the street, hands behind their backs. Some were bloodied.
Shops and offices in La Paz were shuttered on Monday in the wake of looting that broke out late on Sunday in some parts of La Paz and El Alto.
The police - largely confined to barracks since riots broke out on Friday, with many units joining the protests - were returning to the streets, police chief Vladimir Yuri Calderon said.
Several of Morales' ministers and top officials resigned after his announcement - including many who sought refuge at the Mexican embassy - raising the question of who was in charge, given that vice president Alvaro Garcia Linera also resigned.
Under the constitution, power then passes to the president of the Senate and the speaker of the lower house of Congress, in that order. But they have resigned, too.
Anez stepped in on Sunday to say she would assume the presidency, given her position as deputy senate leader.
The 52-year-old is likely to be tasked by Congress to oversee fresh elections and a transition to a new government by January 22.
Lawmakers are due to meet on Tuesday to begin the process.