Raja Lahrasib Khan, 56, a naturalized U.S. citizen of Pakistani origin, was charged Friday with attempting to provide material support to a foreign terrorist organization.
According to the criminal complaint, Khan also discussed a possible bomb attack on an unspecified U.S. stadium this summer. Speaking with a man identified only as Individual B, Khan allegedly said bags containing remote-controlled bombs could be placed in the stadium and then, "boom, boom, boom, boom," prosecutors said.
The balding, bearded Khan, clad in a wrinkled nylon jacket, rumpled pants and sneakers, appeared before U.S. Magistrate Geraldine Soat Brown on Friday. She ordered him held pending a status hearing set for Tuesday.
He was represented by Daniel P. McLoughlin, a staff attorney with the federal defender program. McLoughlin declined to comment after the hearing but told Soat Brown he would probably withdraw from the case and another attorney would be appointed to defend Khan.
U.S. Attorney Patrick J. Fitzgerald said there was no imminent danger to the Chicago area.
Prosecutors also said the investigation was unrelated to one that produced charges against an American citizen, David Coleman Headley, and a Canadian businessman living in Chicago, Tahawwur Rana, in the November 2008 terrorist attacks that left 166 people dead in the Indian city of Mumbai.
Ilyas Kashmiri, a terrorist leader believed to be based in the tribal areas of western Pakistan, is charged in that indictment along with Headley and Rana in connection with a planned attack on a Danish newspaper that published cartoons depicting the Prophet Muhammad in 2005.
Headley pleaded guilty last week to the charges. Rana has pleaded not guilty to conspiring to provide material support to terrorists in Denmark and India.
The complaint against Khan said he told an undercover agent he was acquainted with Kashmiri. Authorities say Khan claimed to have known Kashmiri for 15 years and said he came to believe that Kashmiri was receiving orders from Osama bin Laden. Prosecutors have said that Kashmiri maintains close ties with at least one al-Qaida leader.