Eleven people were injured, including a police officer, and nine were taken to a hospital, the police chief, Peter Newsham, said at a news conference on Wednesday, NYT reports.

Photos and videos on social media showed people kicking and punching as the police tried to intervene. At one point, a man threw a bullhorn, two men could be seen bleeding from the head, and another man was on the ground being violently kicked.

The fighting poured into a park across the street as uniformed police officers, some in helmets and swinging collapsible batons, tried to restore order. Men in dark suits could be seen in the videos, punching and kicking protesters. The Anadolu Agency, a state-owned Turkish news service, reported that members of the president’s security team were involved in the fighting.

Read alsoReuters: Council of Europe puts Turkey on notice over rights, democracy“Yesterday we witnessed what appeared to be a brutal attack on peaceful protests,” Chief Newsham said.

“First and foremost I will say that that is not something that we will tolerate here in Washington, D.C.,” he said. “This is a city where people should be able to come and peacefully protest.”

In a statement on Wednesday, the police said the fight stood “in contrast to the First Amendment rights and principles we work tirelessly to protect each and every day.”

RFE/Rl reports President Erdogan's security guards were among the assailants.