Bolivian opposition senator Jeanine Anez has proclaimed herself the country's interim president in an effort to fill the power vacuum left by the abrupt resignation of Evo Morales, who immediately condemned the move as a "sneaky coup."

Key points: Ms Anez said new elections would be called as soon as possible

Ms Anez said new elections would be called as soon as possible Exiled president Evo Morales called Ms Anez "a coup-mongering right-wing senator"

Exiled president Evo Morales called Ms Anez "a coup-mongering right-wing senator" The death toll has risen to seven people since public unrest began in October

Ms Anez's declaration comes just hours after Mr Morales flew off to self-exile in Mexico as his life was in danger.

Politicians had earlier been summoned to formalise Mr Morales resignation and confirm Ms Anez as interim president.

Instead, Ms Anez, a women's rights activist and former TV presenter, declared herself interim president when the session failed to reach a quorum, with many representatives staying away amid blockades and continuing protests by Mr Morales' supporters.

Protesters and Morales supporters continue taking to the streets. ( AP: Natacha Pisarenko )

The Constitutional Court later endorsed her appointment.

"We want to call new elections as soon as possible," Ms Anez said in a speech to Congress, with only Morales opponents present.

"It's a commitment we have made to the country and of course, we will fulfil it," she said.

Later, clutching a bible and wearing the presidential sash over her black jacket, the senator addressed supporters from the balcony of the government palace.

Ms Anez said they will hold new elections as soon as possible. ( AP: Juan Karita )

Ms Anez said earlier she was confident that enough senators would reach the Senate to form a quorum — 19 of the 36 were needed to do so.

Tweeting from exile in Mexico, Mr Morales immediately condemned what he called "the sneakiest, most nefarious coup in history".

Mr Morales called Ms Anez "a coup-mongering right-wing senator" and said she had "declared herself … interim president without a legislative quorum, surrounded by a group of accomplices."

Leaders of the biggest party, Morales' Movement for Socialism (MAS), had requested guarantees to be able to attend the session, but stayed away.

New protests erupt

Supporters of former president Evo Morales carry "wiphala" flags that represent indigenous peoples. ( AP: Natacha Pisarenko )

Security forces fired tear gas in street clashes in La Paz immediately after the Congress session.

Carlos Mesa, the centrist candidate defeated by Mr Morales in the tainted October 20 presidential elections, tweeted his congratulations to Ms Anez, who has promised a new government would be installed by January 22.

Powerful opposition figure Luis Fernandez Camacho, regional leader in eastern department of Santa Cruz, announced he had lifted strikes and blockades called three weeks ago in protest at Mr Morales' disputed re-election.

Mr Morales resigned after losing the support of the security forces.

Police hold back Morales supporters near the senate after Ms Anez declared herself the country's interim president. ( AP: Natacha Pisarenko )

Dozens of officials and ministers also stepped down, some seeking refuge in foreign embassies.

Ms Anez found herself next in line to take over after the resignations of vice president Alvaro Garcia Linera, the Senate president, and the speaker of the lower house of Congress.

'He saved my life'

Earlier on Tuesday (local time), Mr Morales vowed to continue "the struggle" after arriving in Mexico where he has been granted political asylum.

Mr Morales thanked left-wing ally and Mexico President Andres Manuel Lopez Obrador, saying "he saved my life," and vowed to remain in politics despite having left his homeland.

Mexican Foreign Minister Marcelo Ebrard welcomed former Bolivian president Evo Morales in Mexico City on Tuesday. ( AP: Eduardo Verdugo )

Grinning and waving as he left the Mexican military plane that had picked him up from Bolivia late on Monday night (local time), Mr Morales was welcomed by Foreign Minister Marcelo Ebrard.

On Monday, the armed forces pledged to help police take back the streets from violent groups that have wreaked havoc since the controversial October 20 election that saw Mr Morales win an unconstitutional fourth term.

Security forces deployed in La Paz on Tuesday, where Mr Morales' supporters marched through the centre to congregate in San Francisco Square near the Congress.

'Racists and coup plotters'

Bolivia's attorney general, Juan Lanchipa, said on Tuesday (local time) that seven people have died in unrest since the election.

The United States has warned its citizens against travel to Bolivia, ordered its diplomats' family members to leave and authorised non-emergency employees to depart due to the unrest.

Mr Morales, a former coca farmer who was Bolivia's first indigenous president, said his opposition rivals, Mr Mesa and Luis Fernando Camacho, "will go down in history as racists and coup plotters".

He was Latin America's longest-serving leader until Sunday.

AFP/AP