The case, being heard at the Seoul Central District Court, is part of a series of legal proceedings against Yoon following his removal from office last year after a brief imposition of martial law that triggered political turmoil in the country.

Prosecutors allege the drone operation heightened military tensions with North Korea and risked exposing sensitive information about South Korea’s military capabilities after one of the drones crashed.

The charges include benefiting the enemy, a provision that can apply even without direct coordination if national security interests are harmed.

Yoon has denied the allegations, with his legal team stating he did not take any action that could provoke a military confrontation with North Korea.

The trial is one of eight cases currently involving Yoon, reflecting the legal fallout from his presidency and the controversial martial law declaration. The court is expected to issue a ruling at a later date.

Emir Balat, 18, and Ibrahim Kayumi, 19, both from the Philadelphia area, entered their pleas during a brief court appearance following their arrest over an alleged March 7 incident targeting an anti-Islam demonstration outside Gracie Mansion, according to court filings and statements from federal prosecutors.

Authorities allege the two men traveled from Pennsylvania to New York with the intent to carry out an attack on the protest, which was organized by activist Jake Lang, a critic of Mayor Zohran Mamdani.

Prosecutors said the defendants deployed two improvised explosive devices containing triacetone triperoxide (TATP) and shrapnel, but the devices failed to detonate.No injuries were reported, and law enforcement officers detained the suspects shortly after the attempted attack.

The mayor and his wife were not present at the residence at the time, officials said.According to a federal complaint, investigators recovered dashcam footage from the suspects’ vehicle in which they allegedly discussed plans to kill as many as 60 people in an effort to “start terror.”

Prosecutors also said the defendants told police they were motivated by the Daesh group.Balat’s legal counsel declined to comment following the hearing, while attorneys representing Kayumi did not immediately respond to requests for comment.

The case highlights ongoing concerns among U.S. authorities over self-radicalized individuals and the use of easily assembled explosive materials such as TATP, which has been used in several past attacks due to its relative accessibility despite its volatility.

The defendants are scheduled to return to court on June 16.