Police in Charlottesville came under criticism for failing to keep apart warring white nationalists and counterprotesters who battled it out in the city streets Saturday amid what at first seemed an anemic response from authorities.

Anger over how the police responded came from all directions and intensified after the death of a woman struck by a car that plowed into a group of counterprotesters. Experts said police appeared outnumbered, ill-prepared and inexperienced.

“The worst part is that people got hurt, and the police stood by and didn’t do a g------- thing,” David Copper, 70, of Staunton, Va., said after an initial morning melee at a park that went unchecked by police for several minutes.

Fourteen people were injured in clashes, and 19 others were hurt in the car crash. Later, two Virginia State Police troopers died when their helicopter smashed into trees at the edge of town and burst into flames. The loss of the police officers only compounded the calamity on a day that pushed police, city officials and residents to their limits.

Cable news replayed a seemingly endless loop of the early violence at Emancipation Park, which police in riot gear had surrounded on three sides, although they seemed to watch as groups beat each other with sticks and bludgeoned one another with shields. Many on both sides came dressed for battle, with helmets and chemical irritants.

At one point, police appeared to retreat and then watch the beatings before eventually moving in to end the free-for-all, make arrests and tend to the injured. Gov. Terry McAuliffe (D) declared a state of emergency about 11 a.m. and activated the Virginia National Guard.

“The whole point is to have overwhelming force so that people don’t get the idea they can do these kinds of things and get away with it,” said Charles H. Ramsey, who headed both the District and Philadelphia police departments.

Demonstrators and counterdemonstrators “need to be in sight and sound of each other, but somebody has to be in between,” he said. “That’s usually the police.”

Complicating the dynamics was the fact that several dozen groups of armed militias — men in full camouflage toting assault-style weapons — were in the middle of the crowds. Some claimed that they were there to keep the peace, although none appeared to try to stop the skirmishes.

Cornel West, the prominent professor and writer who attended a morning church service at First Baptist Church in Charlottesville with a large group of clergy members, said “the police didn’t do anything in terms of protecting the people of the community, the clergy.”

West said that “if it hadn’t been for the anti-fascists protecting us from the neo-fascists, we would have been crushed like cockroaches.”

Richard Spencer, the white nationalist and one of the leaders of the rally, said police failed to protect groups with which he is affiliated. “We came here as a demonstration of our movement,” Spencer said. “And we were effectively thrown to the wolves.” The police, he said, “did not protect us.”

Local and state authorities declined to address specific questions about how the demonstration was handled or their strategy for the day. The city’s mayor, police chief, city manager and McAuliffe also did not answer questions at an early-evening news conference.

Al Thomas, the police chief, said only that the city will be “reviewing events of the day over coming weeks and months.”

McAuliffe thanked law enforcement officers and noted that “this could have been a much worse day today.” He put the blame squarely on the white nationalists “who came here to hurt people.”

He added, without mentioning a specific incident, “And you did hurt people.”

Lt. Joseph Hatter, a commander with the Charlottesville police, said officers tried to create separate areas for protesters and counterprotesters to “reduce the violence.” But, he conceded: “It didn’t work, did it? I think there was a plan to have them separated. They didn’t want to be separated.”

About the apparent delay in reacting to the violence, Hatter said, “I don’t know that we did wait. I think we did the best we could under the circumstances.” He declined to elaborate.

State Del. David J. Toscano (D-Charlottesville), minority leader of Virginia’s House, praised the response by Charlottesville and state police.

“Things were getting out of hand in the skirmishes between the alt-right and what I would describe as the outside agitators who wanted to encourage violence,” he said.

Asked why police did not intervene sooner, Toscano said he could not comment. He said they trained hard to prepare for the demonstration “and it might have been that they were waiting for a more effective time to get people out” of the park.

Experts on handling large demonstrations said authorities in Charlottesville are likely not as prepared for such events, which occur with more regularity in such cities as New York and Washington. They also said that separating antagonists is paramount.

“Big cities handle this stuff all the time,” said Eugene O’Donnell, a former police officer and prosecutor in New York City. “It seems an enormous stretch for Charlottesville and even for the state police.”

A professor at John Jay College of Criminal Justice in New York, he added that “planning on paper can vaporize pretty quickly” and “many police think that if you do nothing, it’s less bad than if you do something. . . . Police departments need to learn to strike a balance and create safe zones for people preaching hate.”

But he also said that, too often, the police are faulted for the poor choices of others.

“When people run amok and cause damage, people blame the police,” O’Donnell said. “When police act proactively, they get blamed for overreaching. People ask, ‘Why weren’t you more patient?’ ”

Laura Vozzella and Sarah Larimer contributed to this report. Heim and Silverman reported from Charlottesville. Hermann reported from Washington.