WASHINGTON - Eighteen people linked to an attack on protesters last month — including bodyguards to Turkey's president — face assault charges in Washington, D.C., city officials said Thursday.
Four have been arrested; the remainder are at large.
Watch: Police in Washington Seek Arrest of 16 More in Attack on Anti-Erdogan Protesters
The announcement at a news conference by the city's mayor and police chief follows a nearly monthlong investigation in which police scrutinized video of protesters being kicked and hit near the Turkish ambassador's residence in Washington.
Turkey's President Recep Tayyip Erdogan was sitting in a car nearby when the incident occurred. However, the city's police chief said investigators had insufficient evidence to charge Erdogan in what he characterized as a "pretty brutal" attack.
"We don't have any information to suggest that the president committed any crime," Peter Newsham, Washington, D.C.'s police chief, told VOA.
WATCH: DC Mayor on arrests, charges
The Turkish leader said Thursday that he will launch a "political" and "legal" fight over the arrest warrants, according to a report by CNN Turk.
Nine people were injured in the skirmish.
Two suspects were arrested May 16, the day of the incident. U.S. Marshals detained two more on June 14 — one in Virginia and one in New Jersey.
Twelve of the remaining suspects are Turkish citizens and have not been detained. Two more are Canadian, the D.C. police chief said.
Washington Mayor Muriel Bowser told reporters that police compared screen captures from video of the assaults to visa and passport photos to identify the suspects.
"As Americans, the First Amendment grants us the right to assemble and protest peacefully, and here in D.C., we are committed to safeguarding and protecting that right," Bowser said.
Washington police are leading the investigation, in cooperation with federal law enforcement and the U.S. State Department.
Most of the suspects face both felony and misdemeanor assault charges.
"If they attempt to enter the United States, they will be arrested," Newsham said. He repeatedly urged those with an outstanding warrant to turn themselves over to U.S. officials.
"This is the type of offense that is extreme in nature. When you have folks that are peacefully protesting here in Washington, D.C., which is a place where we welcome peaceful protests, and they're attacked for no reason, we think it's extremely important," the police chief said.
Protest turns violent
No Turkish embassy staff were implicated in the scuffle, he added.
The brawl took place outside the residence of Turkey's ambassador to Washington shortly after U.S. President Donald Trump met with Erdogan at the White House. Video of the protest recorded by VOA's Turkish service shows what appear to be security guards and some Erdogan supporters attacking a small group of protesters.
WATCH: VOA Turkish service video of the incident
Men in dark suits and others were recorded repeatedly kicking one woman as she lay curled up on a sidewalk. Another wrenched a woman's neck and threw her to the ground. A man with a bullhorn was repeatedly kicked in the face.
After police officers struggled to protect the protesters and ordered the attackers to retreat, several suspects dodged the officers and continued the attacks.
The Turkish Embassy claimed without evidence that Erdogan's bodyguards were acting in "self-defense" during the incident, and that the protesters were affiliated with the PKK (left-wing Kurdistan Workers' Party).
"In Washington, D.C., we do not care particularly what your views are, what you support, or what you do not support," Newsham told reporters Thursday, when asked about the demonstrators' affiliation. "Our role … is to make sure you can do so safely."
Some suspects have not been identified. Washington police plan to release images from the scene to help find out who the alleged attackers are.