One of the groups marched across the city towards the square in front of the city court, where they were met by another group, BLM activists, who also had rifles and pistols.
The sides did not use weapons and only engaged in disputes in a raised voice. Several times, it led to scuffles, but those involved in fights were quickly separated by their comrades.
BLM activists have been chanting slogans calling for an investigation into the killing of African-American woman Breonna Taylor, who was fatally shot by police earlier this year.
No police officers have been dispatched to the square. "I imagine they have more urgent matter", one of the organizers of the first group's march, who had been chanting slogans in support of law enforcement officers, said.
Police arrived later when the members of the first group, taunted by their opponents, left the square. The officers pushed the crowd back from the road and left when order was restored.
Louisville is expected to host another march later on Saturday, in particular, a rally by the NFAC, which positions itself as a more radical alternative to the BLM.
Taylor was killed in her Louisville home in March when police officers were executing a no-knock drug search warrant late at night. Her boyfriend fired the first shot in self-defense, fearing burglars, which prompted the four white police officers to unleash a hail of bullets on the house, hitting Taylor eight times.
The killing of the 26-year-old African American medical technician was initially overshadowed by the onset of the coronavirus pandemic, which began to sweep the country around the same time. Activists, celebrities, and demonstrators have since made it a point to keep her name in the news cycle and call for justice over her death. The officers have yet to face any legal repercussions over the killing.