A man alleged to be supplying military-grade weapons and ammunition to the Islamic State in Iraq and Syria (ISIS) was ordered held without bail, the New York Daily News reported Monday.

Donald Ray Morgan, who also goes by the alias "Abu Omar al Amreeki," was arrested Aug. 2 at New York's John F. Kennedy airport after returning from an eight-month stay in Lebanon. He was charged with being a felon in possession of firearms.

During a bail hearing in Brooklyn federal court last week, prosecutors presented evidence suggesting Morgan trafficked in guns for ISIS and argued for his continued detention pending trial. He has been convicted previously of firing a gun, the report added.

Federal agents were alerted to Morgan after they came across his Twitter posts pledging allegiance to ISIS and calling for jihad in Syria, Iraq, and possibly the United States. Morgan also referred to himself as a mujahid, or Islamic holy warrior.

The U.S. Attorney's office in the Eastern District of New York confirmed reports that Morgan "expressed his allegiance to the leader of ISIS on his twitter account: Abu Omar al Amreeki." His Twitter account appears to have been disabled.

The judge has ordered the case transferred to Morgan's home state in North Carolina.