MST members were demonstrating at the entrance of the neighborhood when the incident happened, in order to pressure local authorities over water supplies.
The Landless Workers Movement, or MST, condemned Thursday the killing of one of their members, hit by a truck in Sao Paulo in the morning, arguing the crime was the result of a strategy attempting to spread fear among social movements.
A man in a truck entered at full speed the Marielle Vive camp in the town of Valhinhos in Sao Paulo, as he was making a food delivery.
The assault left one 72-year-old man dead, identified as Luiz Ferreira da Costa, and more people injured.
The MST demanded sanctions immediately in a statement saying the hitman "acted under the atmosphere of terror against grassroots movements, promoted by irresponsible authorities within the Brazilian government."
Marielle Vive's urban area houses more than 1,000 families and was set up on April 14, 2018, after a Sao Paulo court ruled that the land lot was suited for real estate speculation.