The match which ended 1-0 at the Maracana Stadium, saw a pre-game brawl in the stands, prompting Messi to express his concerns about the situation.
“We saw how (police) were hitting the people; it already happened in the Libertadores final.
“They were more focused on that than on the game. We went to the locker room because it was the best way to calm everything down; a tragedy could have happened.
“We are a family. We decided to play to make the situation more calm,” Messi added.
He later took to Instagram, calling for an end to such incidents.
During the pre-game turmoil, players from both teams attempted to intervene, with Argentina goalkeeper Emiliano Martinez seen trying to disarm a police officer.
The match was later delayed for 22 minutes as Argentina insisted on returning to the pitch only when the situation was under control.
Despite the off-field chaos, Argentina’s win secured their position at the top of South American World Cup qualifying with 15 points, while Brazil currently holds the sixth position with seven points after six games.