Later, just as the city seemed to be quieting down, a Virginia State Police helicopter deployed to monitor the protests crashed into the woods just outside of town, sending black smoke billowing above the trees.

Robby Noll, a nearby resident, heard the helicopter sputtering and said he saw pieces of the aircraft breaking off as it fell to the ground.

“I turned my head to the sky. You could tell he was struggling to try to get control of it,” he said.

Both troopers on board, Lieutenant Jay Cullen, 48, and Berke Bates, who was one day shy of his 41st birthday, were killed.

The cause of the helicopter crash, which occurred in a nearby wooded area, was under investigation, Virginia State Police said.

Trump tweeted his “deepest condolences to the families & fellow officers of the VA State Police who died today”.

He later added: “Condolences to the family of the young woman killed today, and best regards to all of those injured, in Charlottesville, Virginia. So sad!”

Hundreds had descended on Charlottesville either to march in or rail against a “Unite the Right Rally”. Unrest quickly flared even as riot police and national guard troops flooded the city’s downtown.

White far-right supporters, some wearing hats with Trump’s “Make America Great Again” slogan and others in riot gear with shields and batons, faced off against counter-protesters as each side hurled projectiles at each other before overwhelming the police positioned between them.

VIDEO WARNING: graphic content

State police swooped in with tear gas as one counter-protester who was repeatedly pummelled with sticks and a metal pole was left bleeding profusely.

Many of the far-right supporters brandished Confederate battle flags, considered a symbol of racism by many Americans, while others raised their arms in Nazi salutes.

Anti-racism protesters waved flags from the Black Lives Matter movement, chanting slogans like “We say no to racist fear” and “No Nazis, no KKK, no fascist USA.”

Ambulances quickly arrived at the scene of the car ramming, which a witness said was “intentional” – saying one girl got “tore up” after the car “backed up and they hit again”.

He said the dark sedan “raced down here, jumped over the speed bumps and it backed up and it hit everyone again”.

The male driver was taken into custody and police were treating the incident as a “criminal homicide”, the police chief said.

The suspect was named as James Alex Fields Jnr, a 20-year-old white man from Ohio.

“He has been charged with second degree murder, three counts of malicious wounding and failing to stop at an accident that resulted in a death,” said Colonel Martin Kumer, the superintendent of Albemarle-Charlottesville Regional Jail.

Trump, speaking from his golf course in Bedminster, New Jersey, said the hatred that erupted Saturday has existed in America for “a long, long time”.

“We condemn in the strongest possible terms this egregious display of hatred, bigotry and violence on many sides, on many sides,” he said. “It has no place in America.”

“The hate and the division must stop, and must stop right now.”

But the president stopped short of condemning white nationalist and supremacist groups, and ignored shouted questions from journalists about the groups, which broadly supported Trump in last year’s election.

He was quickly criticised by liberals such as his 2016 election opponent Hillary Clinton, who did not name Trump but tweeted that “Every minute we allow this to persist through tacit encouragement or inaction is a disgrace, & corrosive to our values.”

But a few prominent Republicans were more direct in their criticism.

“Very important for the nation to hear @potus describe events in #Charlottesville for what they are, a terror attack by #whitesupremacists,” Florida Senator Marco Rubio tweeted.

The planned rally never got officially underway, as McAuliffe declared a state of emergency saying authorities could not safeguard public safety. Authorities began clearing Emancipation Park after declaring those gathered there to be part of an “unlawful assembly”.

McAuliffe said he was “disgusted by the hatred, bigotry and violence these protesters have brought to our state over the past 24 hours”.

After Trump criticised the violence and hatred on display, David Duke, a former “grand wizard” of the Ku Klux Klan who had been a key figure at the rally, retorted on Twitter that “I would recommend you take a good look in the mirror & remember it was White Americans who put you in the presidency, not radical leftists.”

Additional reporting by the Guardian and Associated Press