A 19-year-old man from the Chicago suburbs has been indicted by a federal grand jury on charges that he tried to provide support to a terrorist group in his effort to travel to Syria with his younger sister and brother.

Federal prosecutors said that the man, Mohammed Hamzah Khan, was one of several disaffected young Muslims in the West who had become radical in recent years and who had tried to go to the Middle East to fight alongside the Islamic State, also known as ISIS or ISIL. The indictment late Thursday was announced on Friday.

The group, waging war against the governments of both Syria and Iraq, has been listed by the American government as a terrorist organization. Western officials are concerned that alienated men and women will receive military training and then return to commit terrorism in their home countries, a worry that hit home this week in Europe.

In France on Friday, the police killed two French brothers who had been sought in the slayings of 12 people at a Paris newspaper. One of the brothers had received military training from Al Qaeda’s Yemen affiliate during a trip to that country in 2011.