At least seven people were injured – several of whom were stabbed – Sunday when friction between neo-Nazi and counter demonstrators in Sacramento tued violent.

Seven patients were transported to area hospitals, “some with critical trauma stab wounds,” the Sacramento Fire Department said. None of the injuries are believed to be life-threatening, Sacramento Police Officer Matt McPhail said.

The injuries were the result of what the fire department described as a “mass casualty event.”

"It was quite a bit of a melee," SFD public information officer Chris Harvey told The LA Times.

No arrests had been made as of Sunday afteoon, but the original, permitted neo-Nazi rally was officially cancelled, ABC10 reported. That rally was to include factions from the Traditionalist Workers Party, Golden State Skinheads, Blood & Honor, National Socialist Movement and Ku Klux Klan, CBS reported.

The neo-Nazi group had planned a demonstration for several weeks, The LA Times reported, and counter protesters were evidently well organized and prepared for the event. Many carried signs or banners with slogans such as "Many colors one working class! Smash patriarchy and racism." Several protesters had their faces covered with black cloth.

The clashes occurred near the State Capitol.

Video shot by an ABC10 reporter of several fights showed the two groups bashing each other with sticks and throwing objects in a violent, chaotic fracas. Blood stains were visible on the ground and several of those involved were bleeding following the fights, including two neo-Nazis visibly bleeding from their heads.

Police officers witnessed a Klan member stab someone with a knife, an officer told CBS. A counter protester was also found stabbed inside a vehicle, CBS reported.

Califoia Highway Patrol officers managed to break up the fights, but some members of both groups remained in the area for a time.

The Southe Poverty Law Center 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."

The Associated Press contributed to this report.