Police said evacuated the area around the headquarters of the Democratic National Committee in Washington, D.C., after making arrests at a chaotic pro-Palestinian rally Wednesday night.

U.S. Capitol Police said on X that a “large group of illegal protesters…have cleared out, but USCP officers will stay on scene out of an abundance of caution.” They previously put the number of demonstrators at about 150 and said they were “violently protesting in the area.”

Six officers were treated for injuries as a result of the demonstration, and one person was arrested and accused of assault on an officer, Capitol Police said on X.

Capitol Police said in a separate notice to reporters that they had restricted entry and exit to the nearby House office buildings.

“We’re monitoring the situation outside the DNC and are in touch with USCP and Metro Police, who are directing the security response,” A DNC spokesperson said in a statement.

Numerous lawmakers were in the DNC headquarters when the protest erupted.

The top three House Democratic leaders were all inside the DNC headquarters as protests started outside tonight, according to a source familiar with the group of lawmakers attending the DNC event. 

Minority Leader Hakeem Jeffries, Whip Katherine Clark and Caucus Chair Pete Aguilar were in the building with other Democrats for a Democratic Congressional Campaign Committee (DCCC) candidate week leadership reception, according to a source familiar with the group of lawmakers attending the DNC event. 

The source did not say how long the lawmakers were inside.

Spokespeople for Jeffries and Aguilar would not comment on members in attendance, and Clark’s office did not respond to a request for comment.

Capitol Police said that all lawmakers were moved from the area for their safety.

IfNotNow, a group that describes itself as “American Jews organizing our community to end U.S. support for Israel’s apartheid system,” said it was at the protest, and accused officers of being violent toward demonstrators.

“BREAKING: Police are being extremely violent outside @TheDemocrats headquarters,” the group posted on X. “We are linking arms, threatening no one, and begging our politicians to support an end to the killing and the suffering in Gaza. Begging, peacefully, for a ceasefire. And this is the response.”

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Rep. Brad Sherman, D-Calif., posted on X that he was evacuated from the DNC “after pro-terrorist, anti-#Israel protestors grew violent, pepper spraying police officers and attempting to break into the building.”

NBC News hasn’t independently verified Sherman’s characterization of the protest. Capitol Police didn’t immediately respond to a request for comment on his remark about pepper spray being used on police. The Metropolitan Police Department also did not immediately respond to a request for comment.

IfNotNow spokesperson Eva Borgwardt said in a statement that Sherman’s account was inaccurate, adding that the congressman was ” spreading dangerous and reckless misinformation about our nonviolent movement.”

“Calling hundreds of progressive Jews fighting for peace, many of whom have family members in Israel, ‘pro-Hamas’ is beyond the pale and the Congressman should apologize for his remarks,” Borgwardt said.

She added that the protest was “nonviolent” and a “moral act of civil disobedience to call on Democrats to support a cease-fire and an end to our government’s funding of violence against Palestinian civilians by Netanyahu’s far-right government.”

Rep. Sean Casten, D-Ill., posted on X that he was “rescued” from the DNC building by “armed officers” who “did not know the protestors’ intent; they knew only that Members of Congress were inside, could not leave and that protestors would not let police through.”

“Forcing police to guess intent is irresponsible and dangerous,” Casten added.

Video posted to social media appeared to show protesters wearing shirts emblazoned with “CEASE FIRE NOW” clashing with officers on the steps of the DNC, who appeared to be working to remove demonstrators from the scene.

The protest comes a day after thousands gathered in Washington for a March for Israel rally against antisemitism.

The security level for Tuesday’s event was raised to the highest designation. There were no immediate reports of arrests or counterdemonstrations.