Washington (CNN) Leftist protesters burned an American flag outside the White House on Thursday and then clashed with supporters of President Donald Trump, including the far-right Proud Boys group, not long before Trump took the stage for his "Salute to America."

The protests, which turned into violent clashes at times, took place just blocks from crowds who had gathered to watch Trump's July Fourth speech and fireworks displays on the National Mall.

Led by activist Joey Johnson, a group from the Revolutionary Communist Party, USA, linked arms and set an American flag on fire outside as they chanted, "America was never great." The Secret Service intervened quickly to extinguish the fire.

"Burn, baby, burn," the protesters chanted.

In a news release before the event, Johnson said he was leading the protest because "I'm going to be speaking to the people of the world letting them know that there are people inside the borders of this country who stand with the people of the world."

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