Former President Obama tweeted quotes from Nelson Mandela after violent clashes Saturday in what is believed to be the largest white nationalist rally in a decade left three people dead, including a pedestrian killed when a car plowed into a group of counter-protesters.

"No one is born hating another person because of the color of his skin or his background or his religion ... People must learn to hate, and if they can learn to hate, they can be taught to love... ...For love comes more naturally to the human heart than its opposite," Mr. Obama sent in a series of three tweets.

"No one is born hating another person because of the color of his skin or his background or his religion..." pic.twitter.com/InZ58zkoAm — Barack Obama (@BarackObama) August 13, 2017

"People must learn to hate, and if they can learn to hate, they can be taught to love..." — Barack Obama (@BarackObama) August 13, 2017

"...For love comes more naturally to the human heart than its opposite." - Nelson Mandela — Barack Obama (@BarackObama) August 13, 2017

A 32-year-old woman was killed crossing the street when a driver plowed into a group of counter-protesters and two Virginia State Police troopers were killed in a helicopter crash near the city. Nineteen others were injured.

The violence began Saturday when 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, but police broke up the demonstration before it began. Images of white nationalists carrying torches electrified social media on Friday night.

Get Breaking News Delivered to Your Inbox

Mr. Obama's tweets came hours after President Trump was criticized for remarks when he condemned hatred and bigotry "on many sides."

"We're closely following the terrible events unfolding in Charlottesville, Virginia," Mr. Trump said to reporters at his resort in Bedminister, New Jersey. "We condemn in the strongest possible terms this egregious display of hatred, bigotry and violence, on many sides ... On many sides. Not Donald Trump, not Barack Obama. This has been going on for a long, long time."

In his remarks, Mr. Trump did not mention the displays of white nationalism or Nazi symbols present in Charlottesville Saturday.

Mr. Trump later tweeted "No matter our color, creed, religion or political party, we are ALL AMERICANS FIRST."

We must remember this truth: No matter our color, creed, religion or political party, we are ALL AMERICANS FIRST. pic.twitter.com/FesMiQSKKn — Donald J. Trump (@realDonaldTrump) August 12, 2017

Democrats and some Republicans called out Mr. Trump directly for refusing condemn white nationalists.

There is only one side. #charlottesville — Joe Biden (@JoeBiden) August 12, 2017

Repeat after me, @realDonaldTrump: white supremacy is an affront to American values. #Charlottesville — Nancy Pelosi (@NancyPelosi) August 12, 2017

We should call evil by its name. My brother didn't give his life fighting Hitler for Nazi ideas to go unchallenged here at home. -OGH — Senator Hatch Office (@senorrinhatch) August 12, 2017

Mr. President - we must call evil by its name. These were white supremacists and this was domestic terrorism. https://t.co/PaPNiPPAoW — Cory Gardner (@SenCoryGardner) August 12, 2017

Mr. Trump's 2016 opponent, Hillary Clinton, did not mention the president directly but she did write "every minute we allow this to persist through tacit encouragement or inaction is a disgrace, & corrosive to our values."

My heart is in Charlottesville today, and with everyone made to feel unsafe in their country. — Hillary Clinton (@HillaryClinton) August 12, 2017

But the incitement of hatred that got us here is as real and condemnable as the white supremacists in our streets. — Hillary Clinton (@HillaryClinton) August 12, 2017

Every minute we allow this to persist through tacit encouragement or inaction is a disgrace, & corrosive to our values. — Hillary Clinton (@HillaryClinton) August 12, 2017

Virginia Gov. Terry McAuliffe strongly denounced the protests and declared a state of emergency.

"We are stronger than you," the Democratic governor told reporters. "You have made our commonwealth stronger. You will not succeed. There is no place for you here."