Turkish President Recep Erdogan's visit to the United States this week was quickly overshadowed by his security detail's manhandling of journalists, which only seemed to validate criticisms that he's an oppressive strongman with little regard for a free press.

Erdogan's security guards assaulted reporters in Washington, D.C., this week, drawing condemnation from several media advocacy groups, including Reporters Without Borders.

"This is not the first time such unacceptable behavior has been used against journalists covering a visit by the Turkish president to the United States," the group said in a statement Friday.

Erdogan was scheduled to deliver an address on free speech Thursday at the Brookings Institution. Before he even spoke a word, however, his security team harassed and physically assaulted several reporters, some of whom they managed to remove forcibly from the scheduled event.

All this came despite that the journalists they removed were included on the event's guest list. It took the staff of the Brookings Institute to get Erdogan's men to back down.

One reporter, Adem Yavuz Arslan, Washington correspondent of Turkey's Ozgur Dusunce Daily newspaper, was ejected by Erdogan's men, who then reportedly told him, "You're not allowed to be in here, you're a traitor."

"[O]utside," the reporter said, "they still harassed me and threatened me."

The Brookings staff eventually allowed the Arslan back in, insisting to Erdogan's men that the reporter was there as their guest.

Even after being allowed back inside, however, the Brookings people reportedly had to assign U.S. security officials and a Secret Service agent to protect the Arslan, "since Turkish security guards continued to 'verbally harass, insult and threaten' him," RFS said.

Arslan said this is par for the course for Erdogan's staff.

"Erdogan's guards are not committing these barbaric acts against independent media on their own," he said. "I'm pretty confident they have their orders."

He wasn't the only reporter to have been accosted by the president's guards.

A second Turkish journalist, Emre Uslu, said he was kicked outside the Brookings event by Erdogan's bodyguards, and said he was barred from entry, according to the Associated Press.

Another reporter, this one an American, was reportedly kicked in the chest as he tried to film the altercation, AFP reported.

"RSF condemns the Turkish security guards' unacceptable behavior towards journalists covering this important event in Washington, DC," RSF's US Director Delphine Halgand said in a statement. "Not only is Erdogan abusing freedom of the press on a regular basis in his own country, but now his security team believes they can obstruct freedom of the press in the United States."

The National Press Club added to the fray this week, and its president, Thomas Burr, said in a statement, "Turkey's leader and his security team are guests in the United States."

"Erdogan doesn't get to export such abuse," he added.

This isn't even the first time that the Turkish president's men have roughed up journalists during a visit to the United States.

"In September 2014, Erdogan's bodyguards attacked two Turkish journalists in New York during a visit between the Turkish leader and United States Vice President Joe Biden," RSF reported.

"One of the reporters was Adem Yavuz Arslan, the very same journalist attacked yesterday. Arslan said the president's nephew, Ali Erdogan, who was a member of his security detail, evicted him from the hotel at the behest of one of the president's advisers. Once he was on the street, two other advisers, Senol Kazanci and Aydin Unal, threatened him. 'Your existence is a crime,' one of them said. Two unidentified men then physically attacked Arslan in the street in front of the hotel," they added.

Erdogan's penchant for stifling and intimidating the press is reflected in the fact Turkey is rated 149th out of 180 countries on in RSF's World Press Freedom Index.

Erdogan met with both President Obama and Vice President Joe Biden Friday to discuss a host of topics, including ongoing efforts to fight terrorism worldwide.