SAN FRANCISCO: Ten people suffered stab wounds and other injuries on Sunday after members of a white nationalist group that planned to rally outside the California state Capitol building in Sacramento clashed with a larger group of counter-protesters, authorities said.

The fight broke out when about 30 members of the Traditionalist Worker Party (TWP) gathering to rally around noon Sunday were met by about 400 counter-protesters, California Highway Patrol Officer George Granada said.

As people tried to leave the area, smaller fights broke out, Granada said.

Of the injured, two were taken to the hospital with critical stab wounds, but they were expected to survive, officials said.

Police were investigating two assaults that happened outside the Capitol grounds, but no arrests have been made, the Sacramento Police Department said in a statement.

The Capitol was on lockdown until protesters cleared the area.

Videos from the melee posted on social media showed mounted police officers dispersing a group of mostly young people, some with their faces covered, while some throw stones toward a man holding a stick and being shielded by police officers in riot gear.

A KCRA-TV reporter and his cameraman were caught in an altercation with protesters who shouted “no cameras” as they tried to grab their equipment and shove them away from the crowd.

Sacramento Fire Department spokesman Chris Harvey said nine men and one woman, ranging from 19 to 58 years old, were treated for stab wounds, cuts, scrapes and bruises.

“There was a large number of people carrying sticks and rushing to either get into the melee or see what was going on,” Harvey said.

The victims were all present while the protest took place, said Sacramento Police spokesman Matt McPhail but he said it was still unclear whether and how they were involved.

The TWP had scheduled and received a permit to protest for two hours in front of the Capitol.

Law enforcement was aware of the counter-protest effort and police deployed more than 100 officers to the Capitol, McPhail said.

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".

Matthew Heimbach, chairman of the TWP, told the Los Angeles Times that his group and the Golden State Skinheads organised the Sunday rally.

Heimbach said that in the clash, one of their marchers had been stabbed in an artery and six of the counter-protesters had also been stabbed.

Vice chairman Matt Parrott, who was not present at the Sacramento rally, blamed “leftist radicals” for instigating the violence.

A message left at a phone number for the TWP was not immediately returned to The Associated Press.

A post recently uploaded to site of the Traditionalist Youth Network (TYN) said TWP members planned to march in Sacramento to protest against globalisation and in defense of their right to free expression. They said they expected to be outnumbered 10-to-1 by counter-protesters.

“We concluded that it was time to use this rally to make a statement about the precarious situation our race is in,” the TYN statement said.

"With our folk on the brink of becoming a disarmed, disengaged, and disenfranchised minority, the time to do something was yesterday."

The clash Sunday follows a confrontation in March between Ku Klux Klan members and counter-protesters in Anaheim, California in which three people were stabbed.