Black activists in the southern city of Porto Alegre where the killing occurred have organized demonstrations outside of Carrefour stores since Friday, with another major protest being held on Monday night.
The hundreds of protesters waved flags and chanted outside a Carrefour store in the east of the city at dusk, holding signs such as "Black Lives Matter. Stop killing us." Stickers calling for a boycott against Carrefour were circulated widely.
Shares in Carrefour plummeted more than 5% on Monday, erasing 2.16 billion reais ($400 million) in market value. In mid-morning trading on Tuesday, shares were down 0.6%.
The Brazilian unit of France-based Carrefour SA said in a securities filing on Tuesday, its first public notice to investors on the killing, that it would donate all the profit that stores nationwide made on Nov. 20 to projects fighting racism, and 25 million reais ($4.6 million) to a fund promoting racial inclusion.
On Monday night, some protesters began tearing down sections of the fence surrounding the supermarket and set tires on fire. A smaller group of the protesters threw stones at police armed with riot gear.
Police fired tear gas, rubber bullets and charged on horse back.
In a video circulated widely on social media, the two security guards were shown punching and pinning to the ground 40-year-old Joao Alberto Silveira Freitas. The two men have been arrested and Carrefour Brasil said it has terminated its contract with the security firm.
It was not clear if racism was a factor in the killing.
On Monday, Carrefour Brasil said in a statement that it recognized the protests as legitimate.
"We share the same sentiment and are open to start a discussion in society, aimed at finding solutions so that cases like this do not happen again," the supermarket chain said.
($1 = 5.4150 reais)
(Reporting by Diego Vara in Porto Alegre, additional reporting by Carolina Mandl in Sao Paulo, writing by Jake Spring; Editing by Kevin Liffey and Alistair Bell)
By Diego Vara