Prosecutors say the 27-year-old identified only as Hassan F. participated in the beheading of a religious leader in the city of al-Sukhnah in Homs province and was also involved in the killings of at least 25 people.

At the start of the trial yesterday, his defense lawyer asked the court to reject many of the pre-trial testimonies implicating his client, in part because they were by people who did not personally witness the alleged crimes.

According to his indictment, Hassan F. was the commander of a small, armed ISIS unit, washingtonpost.com says.