The Bolivian prosecutor's office said on Friday it had filed charges of "genocide" and other crimes against former acting president Jeanine Anez, over the death of 20 opposition protesters in 2019.

Attorney General Juan Lanchipa said he had presented documents "against citizen Jeanine Anez" before the country's Supreme Court of Justice, including charges for "genocide," which carries a sentence of 10 to 20 years in prison, according to the Bolivian penal code.

The conservative Anez came to power in November 2019 after her predecessor and rival, former president Evo Morales, resigned following weeks of protests over his controversial re-election to an unconstitutional fourth term.

He fled the country after an election audit by the Organization of American States (OAS) found evidence of fraud.

After the election, at least 37 people died in violence that flared between supporters and opponents of Morales, as well as between protesters and the security forces.

Most of the deaths came in clashes between Morales supporters and security forces after the socialist leader's flight.

The specific accusation against Anez relates to two incidents in November 2019 in which a total 22 people died. A report released by the OAS on Tuesday described those incidents as "massacres."

Lanchipa said they had been "provisionally classified as genocide, serious and minor injury and injury followed by death."

Bolivia's opposition has decried the lack of separation of powers in the country, saying the courts, electoral body and pubic prosecutor's office are all loyal to leftist President Luis Arce, who is also a member of Morales's Movement for Socialism (MAS).

"First of all, we need to reform the judiciary because it is not independent or autonomous," said centrist lawmaker Alejandro Reyes.

Former interim Bolivian president Jeanine Anez speaks with her lawyers in March 2021 from a prison cell after being arrested in La Paz
Former interim Bolivian president Jeanine Anez speaks with her lawyers in March 2021 from a prison cell after being arrested in La Paz AFP / LUIS GANDARILLAS

"As long as there is no judicial reform, we cannot do anything."

However, the case is unlikely to go to court, as for that to happen, the supreme court must ask congress for authorization to hold Anez responsible for what happened.

Authorization could only be given by a two-thirds majority, and although MAS controls congress, it does not enjoy a sufficiently large majority.

While MAS lost the presidency for a year to Anez, it never gave up control of congress.

After Morales resigned, Anez was the most senior parliamentarian left and was sworn in by congress as interim president, despite the lack of a quorum, with MAS legislators boycotting the session.

MAS cried foul and accused the interim government of having pulled off a coup.

Under Anez's administration, Bolivia held peaceful, transparent elections in October 2020 in which Morales's protege Arce stormed to a landslide victory.

He subsequently vowed to go after those he accused of staging a coup.

Anez was arrested in March 2021 on accusations of leading a coup against Morales. She also faces other charges of terrorism, sedition and conspiracy. She has remained in pre-trial detention since then.

Her detention elicited widespread international condemnation.