A black man who died after being beaten by supermarket security guards in the city of Porto Alegre on the eve of Black Consciousness Day has sparked outrage across Brazil after videos of the incident circulated on social media. Footage showed João Alberto Silveira Freitas being punched in the face just outside the doors of a Carrefour supermarket, late on Thursday. Other clips showed Freitas’ being kneeled on. Dozens of protesters entered a Carrefour in Brazil’s capital, Brasilia, on Friday morning, chanting “Black lives matter!” One held a sign reading: “Don’t shop at Carrefour. You could die”. Inside another Carrefour in Rio de Janeiro, protesters shouted “Carrefour Killer!” as a black man lay still atop the conveyor belt of a checkout. They forced the store’s closure. In Sao Paulo, protesters smashed the front window of a Carrefour, scattered goods from shelves all over the store’s floor and set a fire that employees hurried to extinguish. Carrefour released a statement lamenting Freitas’ “brutal death”, and said it would end its contract with the security company, fire the store manager who was on duty, and close the Porto Alegre store out of respect for the victim. The two men who allegedly beat Freitas have been detained and are being investigated for homicide due to the victim’s asphyxiation and his inability to defend himself, said Nadine Anflor, the civil police chief for the southern state of Rio Grande do Sul, where Porto Alegre is capital. One of the men was a temporary military police officer who was off-duty, said Rodrigo Mohr, head of the state’s military police. Black Consciousness Day is observed as a holiday in many parts of Brazil. In Rio on Friday, a group of people participated in a celebration with Afro-Brazilian dance and music in the working-class Santa Marta favela. Members of a samba school performed a ritualistic “washing” of the steps leading up into the hillside neighbourhood. Black and mixed-race people account for about 57% of Brazil’s population but constitute 74% of victims of lethal violence, according to the Brazilian Forum on Public Safety, a non-governmental organisation. The percentage is even higher, 79%, for those killed by police. Local online news site G1 reported that the incident at the Carrefour in Porto Alegre followed a confrontation between Freitas and a supermarket employee, who then called security. Both guards were white, G1 reported.