CHICAGO (AP) — A federal grand jury has indicted a 19-year-old suburban Chicago man on a terrorist charge for allegedly seeking to join Islamic State group militants in Syria.

Prosecutors said Friday Mohammed Hamzah Khan faces a single count of attempting to provide material support to a foreign terrorist organization. Khan has been in federal custody since he was arrested in October at O'Hare International Airport.

Khan was originally charged in a criminal complaint in October. The indictment returned late Thursday formalizes that charge. It carries a maximum 15-year prison sentence and a $250,000 fine.

Khan's defense attorney has called the government's case weak and says Khan appeared to have fallen under the influence of Islamic State group propaganda.

Khan lived with his parents in Bolingbrook. His arraignment is set for Jan. 13.