A congressional aide told The Associated Press that two members of Erdogan's security detail were detained on the scene Tuesday by diplomatic security agents. But the guards quickly claimed diplomatic immunity, and were released after diplomatic security consulted with counsel. The aide was not authorized to speak publicly and requested anonymity to discuss the situation.
The State Department said Wednesday that "violence is never an appropriate response to free speech, and we support the rights of people everywhere to free expression and peaceful protest."
The remarks from Graham and McCain come after Rep. Ed Royce of California, the Republican chairman of the Foreign Affairs Committee, called on the Trump administration to investigate whether criminal charges are warranted against any of the bodyguards.
Royce detailed his request for an inquiry in a letter sent Wednesday to Secretary of State Rex Tillerson and Attorney General Jeff Sessions. He wrote that bodyguards with Erdogan on his official state visit to Washington "viciously beat multiple individuals, throwing them to the ground and kicking them in the head."
The incident occurred after Erdogan arrived after a White House meeting with President Donald Trump. Video shows people pushing past police to confront a small group of protesters across the street in Sheridan Circle.
#Erdoğan'ın korumaları kavgaya karıştı https://t.co/gsi1iQ68Ye #amerikaninsesi pic.twitter.com/Jv3g5E7AVA
— Amerika'nın Sesi (@VOATurkish) May 17, 2017
Attacking the small group of protesters with their fists and feet, men in dark suits and others were recorded repeatedly kicking one woman as she lay curled on a sidewalk. Another person wrenches a woman's neck and throws her to the ground. A man with a bullhorn is repeatedly kicked in the face. In all, nine people were hurt.
Several other Senate Republicans, including Marco Rubio of Florida and Ted Cruz of Texas, called on the Turkish government to immediately apologize for the violence.
In a statement, the Turkish Embassy blamed the violence on the demonstrators, saying they were "aggressively provoking Turkish-American citizens who had peacefully assembled to greet the president. The Turkish-Americans responded in self-defense and one of them was seriously injured."
Tensions between Washington and Istanbul are running high after the Trump administration announced plans to arm Kurdish Syrian militants fighting the Islamic State group despite intense opposition from Turkey, which considers the Kurds as terrorists.
The decision is meant to accelerate the operation to recapture the key Islamic State group stronghold of Raqqa. But Erdogan's government views the Syrian Kurdish group known as the YPG as an extension of a Kurdish terrorist organization that operates in Turkey.
But 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.