The clash happened at the Turkish ambassador's residence Tuesday as President Recep Tayyip Erdogan arrived after a White House meeting with President Donald Trump.
Erdogan then gets out of the auto, and starts to watch how his security detail beats the protesters, while the first bodyguard returns to him, as if briefing on the happening. Nine people were hurt.
"We are communicating our concern to the Turkish government in the strongest possible terms", State Department spokeswoman Heather Nauert said in a statement.
Turkey's official news station, Anadolu, reported however that the bodyguards and Turkish citizens moved on the protesters after the police refused to silence their anti-Erdogan chants.
"If there were any Turkish Embassy officials involved in beating up these protesters, I will call for them to be removed from the country", said Graham, the GOP chairman of the Senate subcommittee that controls the foreign affairs budget.
"The Turkish-Americans responded in self-defense", the statement said. Video shows people pushing past police to confront a small group of protesters across the street in Sheridan Circle.
A Voice of America video showed police officers struggling to protect the protesters and ordering the men in suits to retreat. "There is no excuse for this kind of thuggish behavior", McCain said on his Twitter account. "This is the United States of America".
Police said they had arrested two people for assault and identified them as United States residents, 49-year-old Ayten Necmi of NY and 42-year-old Jalal Kheirabadi of Virginia.
But Trump stood out in his praise for Erdogan in April, surprising the worldwide community when he called the Turkish president to congratulate him on a controversial referendum win that expanded his power.
Court paperwork spells his name Kheirabaoi, but he said that is incorrect. Online court records say he must return to court June 1 and Necmi on July 12.
Trump and his national security team say the Kurdish-led Syrian Democratic Forces, or SDF, is the most effective battlefield partner against the Islamic State in northern and eastern Syria. "It also alleged that the protesters were affiliated with the separatist Kurdistan Workers' Party", or PKK, which has been designated as a terrorist organization by both the United States and Turkey, but a protest leader denied that claim.
Earlier in the day, Foreign Minister Mevlut Cavusoglu said the Trump administration understood Turkey's position against the YPG.
Cavusoglu said Turkey received USA assurances that arms sent to the YPG would only be used against IS and not against Turkey, with a promise to support Turkey's fight against the PKK.