Attorney General William Barr on Thursday was unapologetic for ordering law enforcement to to clear protesters from a street near the White House Monday, asserting that some in the demonstration were throwing "projectiles" and had defied at least three orders to move to accommodate a larger security perimeter.

In his first public comments on the aggressive federal action that continues to fan a firestorm of criticism, the attorney general also defended President Donald Trump's controversial visit to a nearby church later that evening after the street-clearing operation.

"It was not a political act," Barr said of the visit where the president was photographed with a bible. "It was entirely appropriate for him to do."

Barr claimed that his decision to expand the security perimeter around Lafayette Square was made early Monday, well before Trump's decision to visit St. John's Church, and was not coordinated.

The attorney general also disputed that the demonstration near Lafayette Square Monday was peaceful, claiming he observed the projectiles that were available to the protesters.

"I saw the projectiles...when I went to Lafayette Park," Barr said. "We could not continue to protect" federal property and personnel.

The federal action at the park and Trump's visit to the church have been excoriated by religious leaders and lawmakers who asserted that authorities had used the power of the federal government – including National Guard troops – to enable a mere photo opportunity for the president.

Barr, at a Justice Department briefing, was joined by FBI Director Christopher Wray and other federal law enforcement officials who claimed organized groups were at least partly to blame for instigating violence and sowing chaos in some demonstrations that have followed the death of George Floyd at the hands of police in Minneapolis.

The attorney general and the FBI director said some evidence pointed to suspects associated with Antifa, a far-left ideology, and far-right hate groups.

Barr referred to the antagonists as a "witches' brew" of extremist groups.

On Wednesday, federal authorities in Nevada charged three men associated with the far-right group "Boogaloo" movement with conspiracy to cause destruction during demonstrations in Las Vegas.

“Violent instigators have hijacked peaceful protests and demonstrations across the country, including Nevada, exploiting the real and legitimate outrage over Mr. Floyd’s death for their own radical agendas,” Nevada U.S. Attorney Nicholas Trutanich said.

The movement is named for a term used by extremists to signal what they believe is a coming civil war and collapse of society.

“Law enforcement is focused on keeping violence and destruction from interfering with free public expression and threatening lives,” Trutanich said Wednesday

At the Justice Department Thursday, Wray said the violence and destruction of property "has to stop."

"In recent days, the violence, threat to life, and destruction of property that we’ve seen in some parts of the country jeopardizes the rights and safety of all citizens, including peaceful demonstrators," Wray said. "We’re seeing people who are exploiting this situation to pursue violent, extremist agendas... These individuals have set out to sow discord and upheaval, rather than join in the righteous pursuit of equality and justice."