The protesters were chanting anti-Erdogan slogans as he entered the embassy yesterday after meeting with President Donald Trump, Turkey's official Anadolu news agency reported.
Because "police did not heed Turkish demands to intervene," Erdogan's security team and Turkish citizens moved in and "dispersed them," the news agency said.
"What we saw yesterday - a violent attack on a peaceful demonstration - is an affront to DC values and our rights as Americans," DC Mayor Muriel Bowser said in a statement Wednesday.
A Voice of America video showed police officers struggling to protect a small group of protesters across the street from the embassy from being kicked and beaten bloody by a group of men in dark suits who repeatedly refused their orders to stay away.
"This is the United States of America. We do not do this here," Sen. John McCain commented while retweeting the video. "There is no excuse for this kind of thuggish behavior."
Sen Patrick Leahy also tweeted about it, saying "We've got to come back to American values."
The clash left nine people injured. Two men were arrested at the scene, and police intend to pursue charges against others involved as well, the Metropolitan Police Department said today.
"The actions seen outside the Turkish Embassy yesterday in Washington, D.C. Stand in contrast to the First Amendment rights and principles we work tirelessly to protect each and every day," the police statement said.
"We will continue to work with our partners at the United States State Department and United States Secret Service to identify and hold all subjects accountable for their involvement in the altercation."
There may be issues with diplomatic immunity, Police Chief Peter Newsham said at a news conference today. He said police were examining video to identify those responsible. The background of the two men arrested wasn't immediately clear.
Ayten Necmi, 49, of Woodside, New York, was charged with aggravated assault, police said, after a woman who was thrown to the ground and kicked identified Necmi as her attacker.
Jalal Kheirabaoi, 42, of Fairfax, Virginia, is charged with assaulting a police officer, who refused treatment for lacerations to his face.
The biggest dispute between Turkey and the US recently has been the Trump administration's plans to arm Kurdish Syrian militants fighting the Islamic State group.
The US sees the Syrian Kurds as their best battlefield partner on the ground in northern Syria. Turkey insists that these YPG militants and their PYD political party are tied to the Kurdish insurgency in Turkey known as the PKK, which the US, the European Union and Turkey all consider a terrorist organisation.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)