SACRAMENTO — Authorities knew violence was possible as a white nationalist group planned a demonstration at the California Capitol, and they brought in more than 100 officers to patrol the grounds.

But after 10 people were hurt Sunday, they faced criticism about whether they were properly prepared or too slow to get involved when the demonstration quickly turned violent in a clash with a larger group of counter-protesters.

‘‘It was basically a free-for-all,’’ said Cres Vellucci, an observer with the National Lawyers Guild. ‘‘I was just appalled that nothing seemed to be done.’’ He said his group was there to watch for police overreaction, but in this case the opposite happened.

The California Highway Patrol and Sacramento city police failed to separate about 30 members of the Traditionalist Worker Party from about 300 counter-protesters who rushed to confront them, he said.

Law enforcement was slow to protect people who were attacked and slow to get them medical help, Vellucci said.

A CHP spokesman, Officer George Granada, said police had no obligation to make sure members of the Traditionalist Worker Party made it safely to the rally. ‘‘We’re not going to escort people from city streets or wherever they’re coming from,’’ Granada said. ‘‘Everything turned out fairly well. There was violence, but it could have been a lot worse.’’

No officers or bystanders were hurt and less than $1,000 in damage was done to the Capitol when a window in a security pavilion was broken, Granada said.

Sacramento police recovered a loaded 9mm handgun on the Capitol grounds.

The 10 who were taken to hospitals with stab wounds and other injuries are all expected to survive.

No one was arrested, and Granada said arrests may be difficult because many counter-demonstrators wore masks. Police are reviewing surveillance and social media videos.

Sacramento Mayor Kevin Johnson praised police for reacting quickly and limiting injuries. He called the clashes ‘‘simply unacceptable.’’