More than 60 people died in clashes with the police and military in the protests that broke out in December after the ouster of former president Pedro Castillo, leading to one of the country's most violent episodes in the last two decades.
The government has denied that it committed abuses during the protests and said it is collaborating with investigations.
"There were serious human rights violations that must be investigated with due diligence and an ethnic-racial approach," IACHR President Margarette May Macaulay said in a report. "The deaths could constitute extrajudicial executions."
The violent incidents could be classified as a massacre, the document added.
IACHR said a large number of people were killed and injured by impacts of firearms, mainly in the Andean regions of Ayacucho and Puno, where protesters demanded new elections and the resignation of President Dina Boluarte.
The commission visited Peru between Jan. 11 and 13, and met with relatives of the victims, members of the government and civil society.
The commission's report follows a recent publication by Human Rights Watch, which concluded that Peru's army and police were responsible for deaths in the protests.
Peru's attorney general in January launched an investigation against Boluarte, Prime Minister Alberto Otarola and the country's defense and interior ministers on charges of genocide, homicide and serious injuries.
(Reporting by Marco Aquino; Writing by Valentine Hilaire; Editing by Bill Berkrot)
