Sens. John McCain and Dianne Feinstein on Thursday blasted Turkey's president and urged him to punish his security staff for a bloody scuffle with protesters in Washington this week.

"The violent response of your security detail to peaceful protesters is wholly unacceptable and, unfortunately, reflective of your government's treatment of the press, ethnic minority groups and political opponents," the two senators wrote in a letter to President Recep Tayyip Erdogan.

The clash outside a Turkish ambassador's residence Tuesday was caught on video and showed dark-suited Erdogan staff punching and kicking the protesters while being pushed back by police.

At least nine people were injured, including a police officer.

A similar incident occurred outside the Brookings Institution in March 2016 when the Turkish president's security detail clashed with members of the press and protesters.

"The actions of your staff violate the constitutional protections of freedom of the press and freedom of assembly enjoyed by all Americans," McCain and Feinstein wrote. "Your staff's blatant violation of these rights on American soil is an affront to those freedoms and reflects poorly on your government."

Turkey is also a key member of the NATO alliance and the senators wrote that they "expect conduct more appropriate" from a decades-long ally.