One person was killed and others injured Saturday when a car plowed into a group of protesters in downtown Charlottesville, Virginia, hours after police broke up violent confrontations before a rally of white nationalists.
"I am heartbroken that a life has been lost here. I urge all people of good will -- go home," Mayor Mike Singer said on Twitter.
At least nineteen others were hurt - suffering minor to life-threatening injuries, authorities said Saturday.
Charlottesville Police Chief Al Thomas said the crash killed a 32-year-old woman. They had not released her name as of Saturday evening.
The man arrested in the crash is 20-year-old James Fields.
A dozen medics were seen carting the injured back and forth on stretchers. The victims appeared to be counter-protesters but could be residents, CBS News justice reporter Paula Reid reports.
"A car appeared to deliberately mow down pedestrians," eyewitnesses tell Reid.
Video from the scene showed a grey sedan plowing into protesters marching through the downtown shopping district as bystanders screamed for help.
Footage from another angle showed the car speeding in reverse to flee the scene.
White nationalists clashed with counter-protesters hours before the collision in downtown Charlottesville. Alt-right activists and white supremacists planned to protest the city's decision to remove a statue of Confederate General Robert E. Lee from the city's Emancipation Park.
President Trump condemned the violence in a news conference Saturday afternoon.
"We're closely following the terrible events unfolding in Charlottesville, Virginia. We condemn in the strongest possible terms this egregious display of hatred, bigotry and violence, on many sides," he said.
Mr. Trump said he spoke with Gov. Terry McAuliffe over the phone and agreed "that the hate and division must stop and it must stop right now."
He added, "What is vital now is a swift restoration of law and order, and the protection of innocent lives."
Virginia Gov. Terry McAuliffe declared a state of emergency in the city Saturday to aid the state's response to the violence.
The City of Charlottesville also declared the assembly unlawful and officers in riot gear began to clear the area shortly after noon.
"I have a message to all the white supremacists and Nazis who came into Charlottesville today. Our message is plain and simple: Go home. You are not wanted in this great commonwealth. Shame on you. You pretend you are patriots, but you are anything but a patriot," McAuliffe said in a news conference Saturday night.
"You came here today to hurt people and you did hurt people. My message is clear: we are stronger than you. You have made our commonwealth stronger. You will not succeed. There is no place for you here. There is no place for you in America," McAuliffe added.
Jason Kessler, the organizer behind the "Unite the Right" rally, said he plans to sue the city for violating a court order permitting the rally to be held in the park.
"Our First Amendment rights were violated today," Kessler said by phone before the car crash. He said the city of Charlottesville and McAuliffe violated the court ruling because they "didn't like the outcome."
Some protesters who came for the "Unite the Right" rally were armed and dressed in military-like clothing, while others wore shirts with Nazi symbols and quotes from Adolf Hitler. Another read "diversity is just a genocidal scam."
Saturday's confrontation came after a large group of torch-bearing white nationalists marched through the University of Virginia (UVA) campus Friday night, after a judge issued a ruling allowing Saturday's protest to move forward.
UVA cancelled all scheduled events planned for Saturday citing "ongoing public safety concerns," but announced that the college's medical center would remain open.
"The University is monitoring the developments in Charlottesville and continues to coordinate with state and local law enforcement," the school said in a statement.