The U.S. State Department voiced concerns Wednesday about the violent confrontation outside the Turkish embassy in Washington the day before that led to 11 people being injured and two arrests.

“Violence is never an appropriate response to free speech,” the State Department said in a written statement, adding that it was communicating its “concern to the Turkish government in the strongest possible terms.”

Spokeswoman Heather Nauert said, "Violence is never an appropriate response to free speech, and we support the rights of people everywhere to free expression and peaceful protest."

According to initial accounts and video shot at the scene, a fight broke out between a group of men standing outside the ambassador’s residence and another group of men and women standing across the street near Washington’s Dupont Circle.

“We witnessed what appeared to be a brutal attack on peaceful protesters," a police official said on Wednesday.

Witnesses told The Guardian that the fight erupted when the visiting Turkish president’s security attacked protesters carrying the flag of the Kurdish PYD party outside the embassy, hours after Recep Tayyip Erdogan met with President Trump at the White House.

Video footage posted on social media showed some protesters bloodied as others were being beaten on the ground.

“All of the sudden they just ran towards us,” said Yazidi Kurd demonstrator Lucy Usoyan. She said a pro-Erdogan supporter attacked her.

“Someone was beating me in the head nonstop, and I thought, ‘Okay, I’m on the ground already, what is the purpose to beat me?’” she added.

Metropolitan police spokesman Dustin Sternbeck said the altercation broke out between two groups.

"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 everyday," the police department said in a statement issued on Wednesday.

"The Metropolitan Police Department made two arrests following yesterday's incidents and we have every intention to pursue charges against the other individuals involved. 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."

An investigation into the brawl is still ongoing. Police could not confirm that Erdogan's bodyguards were involved.

"This is a city where people should be able to come and peacefully protest," the police official said. "This is not something we can tolerate in our city."

Fox News’ Rich Edson and The Associated Press contributed to this report.