Colombian security forces committed "serious" human rights violations during a crackdown on protests earlier this year that left dozens dead, the United Nations said in a report on Wednesday.

The UN High Commissioner for Human Rights also found that government agents used "unnecessary or disproportionate force" during the demonstrations between April 28 and July 31.

State security forces were guilty of murder, arbitrary detentions, sexual and gender-based violence, and acts of discrimination and racism, the 63-page report said.

The UN said 44 civilians and two police officers were killed in the clashes.

"In at least 28 cases, the alleged perpetrators were members of the public forces," the report said. "Non-state actors" were involved in 10 other cases, it said.

A demonstrator falls as they are hit by water cannon during anti-government protests in Bogota in June 2021
A demonstrator falls as they are hit by water cannon during anti-government protests in Bogota in June 2021 AFP / Juan BARRETO

The public prosecutor's office claims 29 people were killed during the protests, but the South American country's Ombudsman put that figure at more than 60.

The UN also said in the report that 16 victims suffered sexual violence at the hands of security forces.

Demonstrations broke out on April 28, initially against proposed tax hikes that were later ditched, with demonstrators demanding a change in government policies, an end to police repression and greater state support for those affected by the coronavirus pandemic.

Some 42 percent of Colombia's 50 million people live in poverty.

The government blamed dissident leftist guerrillas for the violence.

The UN report also documented "serious acts of violence" against state agents, as well as damage to public and private property.