A grand jury indicted 19 people, including 15 who were identified as Turkish security officials, on criminal charges from violence that occurred near the Turkish embassy in May.

Sixteen of the defendants were charged on June 13 after police said security agents and others attacked protesters during an official visit by Turkey’s president, Recep Tayyip Erdoğan. The indictment named three new defendants, all Turkish security officials.

The indictment lists a charge of conspiracy to commit a crime of violence with a bias crime enhancement for each defendant. Many were also indicted on additional charges.

Relations were severely strained between the United States and Turkey even before the melee, which came as Erdogan arrived May 16 at the Turkish ambassador's residence after a White House meeting with President Donald Trump.

District of Columbia police Chief Peter Newsham said video showed security guards and some Erdogan supporters attacking a small group of protesters. Nine people were hurt.

American officials strongly criticized Turkey's government and Erdogan's security forces for the violence.

The State Department summoned Turkey's U.S. ambassador to complain about the attack shortly after the confrontation. The Turkish Foreign Ministry then summoned America's ambassador to address the treatment of security guards who were briefly detained.

Turkey's U.S. embassy alleged the demonstrators were associated with the PKK, which has waged a three-decade-long insurgency against Turkey and is considered a terrorist group by the United States. Newsham said there was no indication the protesters were part of a terrorist group.