Sacramento Fire Department spokesman Chris Harvey says a rally by KKK and other right-wing extremists groups turned violent when they were met by counter protesters.
Officer Matt McPhail with the Sacramento Police Department says none of the injuries are believed to be life-threatening.
He says a large fight broke out after people carrying sticks rushed into the area where the rally was being held.
Harvey says California Highway Patrol officers managed to break up the large fight but that some members of both groups remain in the area.
A reporter from the ABC News affiliate in Sacramento described the scene saying there is blood on the sidewalk of the park where the violence occurred and that police have taped off the area.
The rally was organized by group affiliated with the Traditionalist Workers Party, with links to white supremacists, who had permits to hold their rally.
The victims were all present while a protest took place, though McPhail said it was still unclear whether and how they were involved.
The Traditionalist Workers Party had scheduled and received a permit to protest at noon Sunday in front of the Capitol. McPhail says a group of counter-protesters showed up to demonstrate against them.
The Southern Poverty Law Center has described TWP as a group formed in 2015 as the political wing of the Traditionalist Youth Network, which aims to "indoctrinate high school and college students into white nationalism."
No arrests have been made.
The Associated Press contributed to this report.
UPDATE: 5 patients transported to area hospitals from Capitol incident, some with critical trauma stab wounds. pic.twitter.com/wO1yqlvfOA— SacFire PIO (@SacFirePIO) June 26, 2016
Mass casualty incident, multiple stabbing victims at State Capitol during rally. SFD crews triaging patients now. pic.twitter.com/0jGU3hpMXs— SacFire PIO (@SacFirePIO) June 26, 2016