Some protesters were taken into custody Monday evening as San Luis Obispo police started to disperse a six-hour long protest.
Starting at around 6:30 p.m., police blocked off the intersection of Santa Rosa and Walnut Street as protesters began to march to the area.
At around 8 p.m., officers gave protesters several warnings to disperse after police said the protest was declared an unlawful assembly, citing public safety risks.
Officers said they would start arresting those who did not leave the area.
Police fired multiple rounds of tear gas to disperse the crowd and a KSBY reporter at the scene witnessed some water bottles and a rock thrown at officers.
A few people were taken into custody while the crowd dissipated.
Law enforcement was expected to remain on scene throughout the downtown area overnight.
The protest started with a rally at Mission Plaza at 2 p.m. Protesters then marched through the downtown area, stopping in front of the San Luis Obispo Police Department, where officers took a knee with the demonstrators.
From there, the crowd continued marching, making their way onto Highway 101, causing authorities to block traffic in both directions.
Protesters said they hoped for police and community members to understand their message.
"We want them to understand that we are scared, that we are just black people and we want them to understand us and care for us," said Cheyenne Brown, protester.
"We just want to make it clear that here and around the nation we will not stand for police brutality that affects blacks and people of color and that's kind of what we're here representing today," said another demonstrator.
In a statement released late Monday night, city officials said police took action to disperse the protesters because there was concern for their safety if they were to march onto the highway again, particularly in the evening hours. Police said they had also received various reports of planned property damage.