Originally Published: 08 JUL 21 02:29 ET

By Stefano Pozzebon

(CNN) -- An international human rights body has accused Colombia's security forces of applying "disproportionate and excessive force," in dealing with street protesters, more than two months since demonstrations began in Bogota, which left dozens dead.

The report by the Inter-American Commission on Human Rights (IACHR), released on Wednesday, adds to criticisms of the government of Colombian President Ivan Duque, who has faced accusations of a heavy-handed crackdown since protests erupted on April 28.

The protests were sparked by a controversial tax overhaul Duque proposed as part of the country's recovery from the economic fallout of the Covid-19 pandemic. Critics argued the changes would hurt the middle class.

The tax reform has since been abandoned. But marches and demonstrations have only increased in scale and pace over a series of issues, including the country's chronic income inequality and allegations of police brutality.

According to human rights organizations in Colombia, more than 70 people have been killed on the streets since the protest begun, they claim often at the hands of the Colombian security forces.

However, the Colombian Attorney General disputes those figures, saying that only 24 deaths have been proven to be linked to the protests. In a statement to CNN, Colombia's National Police said it had opened investigations over 16 cases of alleged murders at the hand of police agents.

The Colombian Foreign Ministry on Wednesday published a statement rejecting some of the actions recommended by the IACHR, saying that "the lethal cases involving members of the security forces are exceptional."

Duque also addressed the report in person, claiming that "nobody can recommend a country to be tolerant with criminal acts."

He said Colombia was a country that "respect the peaceful protest." But added that "the acts of vandalism, urban terrorism, and the roadblocks are being confronted with the constitution and the law."

The IACHR investigates allegations of human rights abuse in the American Hemisphere under the Organization of American States. It has cited security forces' use of non-lethal weapons toward protesters as a particularly worrying cause of injuries and mutilations.

'My brother is dead'

Marlin Niño's brother, Brayan, died on May 1 in Madrid, a suburb of Bogota, after he was hit by a gas canister shot by a police vehicle. After his death, the Colombian attorney general arrested a police major on charges of murdering the 24-year-old protester.

Prior to his detention, the mayor spoke with local media and lamented the death of the protesters, but claimed he followed police protocols in dealing with street demonstrations.

His case is one of sixteen cases of alleged murder at the hands of the police that are being investigated, the Police Inspector General told CNN in a statement.

In an exclusive interview with CNN prior to the publication of the IACHR report, Colombia's Justice Minister Wilson Ruiz pledged that the Colombian government would show zero tolerance toward police abuses. He welcomed the Attorney General's investigation as an opportunity to present evidence to the entire country.

But Niño's sister Marlin told CNN in June that she fears there may be no consequences for her brother's death.

"Sometimes I am so overwhelmed I just don't want to know any more and be over it. My brother's dead... but at the same time I tell myself: today is my brother, tomorrow who else could it be?" she said.

The IACHR report urges Colombia to try cases involving allegations of police brutality in civilian courts, rather than military tribunals to avoid the circumstance of agents being tried by fellow servicemen.

Niño's case is being investigated by both the ordinary Attorney General's office and military justice attorneys

Even before the release of the report, President Duque had announced a reform of the police which includes further accountability mechanism and additional training for the agents in the areas of human rights, one of the recommendations made by the IACHR.

But Duque has so far resisted the recommendation that Colombia separate its police force from the Ministry of Defense, which oversees all security forces in the country.

Ingrid Betancourt, a former presidential candidate who was kidnapped and held for more than six years by rebel guerrillas in the early 2000s, also points to enduring war-like mentality as the next challenge ahead for the reeling nation.

"This is part of what we could have expected, knowing that we were introducing people from the war to the civil society and that we needed to adjust our institutions," she told CNN.

"And now that people don't hear the sound of the gun machines, they want to be in the streets protesting for their rights, and that I think it's good."