California police on Monday were investigating a violent clash between members of a white supremacist group and counter-protesters on Sunday during which 10 people were stabbed and several others injured.
The brawl in the state capital, Sacramento, could fuel concerns about the risk of violence outside the Republican and Democratic party conventions in Cleveland and Philadelphia next month, and in the run-up to the Nov. 8 presidential election.
The Traditionalist Worker Party, a white nationalist group, had called the rally in part to protest against violence that has flared outside recent rallies by presumptive Republican presidential nominee Donald Trump, one of its leaders told Reuters.
The fight broke out at about noon at the start of the rally outside the California State Capitol, the Sacramento Police Department said in a statement.
More than 100 Sacramento police officers were deployed at the event after authorities learned that a group called Anti-Fascist Action Sacramento was planning a counter-protest, police said.
Protesters tried to block Traditionalist Worker Party members from reaching a staging area where they had been given permission by the California Highway Patrol to demonstrate between noon and 2 p.m., police said.
“During the course of the protest, it quickly escalated and turned violent,” the police statement said. “This violence prompted officers to physically intervene to stop anyone else from being injured.”
The Sacramento Fire Department said 10 patients were treated at area hospitals for multiple stabbing and laceration wounds.
At least two assaults took place in the city’s jurisdiction and are being investigated by city police. The rest of the attacks are believed to have happened on Capitol grounds and will be investigated by California Highway Patrol, police said. No arrests have been made.
Since the clash, both groups have said supporters were wounded.
“Regretfully, one of our men was injured and is currently in the hospital,” the Traditionalist Worker Party said in a statement on its website.
Anti-Fascist Action Sacramento said it had suffered a greater number of wounded.
“So far, we know of six comrades who have been injured to a degree that required hospitalization,” the group said on its Facebook page.
Video footage on social media showed dozens of people, some wearing masks and wielding what appeared to be wooden bats, racing across the Capitol grounds and attacking others.
Trump has blamed “professional agitators” and “thugs” for violence that has broken out at some of his rallies.
(Reporting by Laila Kearney; Editing by Daniel Wallis and Frances Kerry)