This photo provided by the Macon County Sheriff's Office in Decatur shows Brendt Christensen, the suspect in the kidnapping of visiting University of Illinois Chinese scholar Yingying Zhang. Picture: Macon County Sheriff's Office via AP

Chicago - A federal judge on Monday ordered an Illinois man charged with abducting a Chinese scholar held without bond in a first court appearance that drew hundreds of demonstrators with signs calling for justice.

Brendt Christensen, 28, was arrested by FBI agents in Champaign, Illinois, on Friday on charges of kidnapping in the disappearance of Yingying Zhang, 26, on June 9, according to University of Illinois Police. Authorities believe she is no longer alive.

The U.S. Attorney's Office said in a statement that agents overheard Christensen while he was under surveillance explaining that he kidnapped Zhang. A search of his cell phone found he had visited a website that included threads on "Perfect abduction fantasy" and "planning a kidnapping," according to the criminal complaint.

This undated photo provided by the University of Illinois Police Department shows Yingying Zhang. FBI is investigating the disappearance of Zhang as a kidnapping. Picture: Courtesy of the University of Illinois Police Department via AP

On June 9, Zhang went to sign a lease for an apartment in Urbana, but missed a connecting mass transit bus, according to an affidavit. As she waited for the next bus, a motorist in a black Saturn Astra pulled up and she got in the vehicle.

Christensen's appearance Monday in US District Court in Urbana drew crowds of supporters, including some holding signs reading "We are with you Yingying."

People line up outside the federal courthouse for first appearance of Brendt Christensen, the suspect in the kidnapping of Yingying Zhang, a Chinese scholar at the University of Illinois. (Picture: Robin Scholz/The News-Gazette via AP

Crowds also marched in support last week during the search for Zhang, a scholar in photosynthesis and crop productivity who came to study at the University of Illinois two months ago.

Yingying Zhang's father Ronggao Zhang, left, and her friend Xiaolin Hou carry a banner as community members join together to walk for Yingying, a Chinese scholar who went missing three weeks ago. File picture: Holly Hart/The News-Gazette via AP

Christensen's attorney, Evan Bruno, said that his client had not been indicted.

"He's presumed innocent of these charges," he said. "There's a lot that the public doesn't know."

If convicted, Christensen could face life in prison, according to the criminal complaint.

The federal court clerk's office said a detention hearing will be held on Wednesday and a preliminary hearing was set for July 14.

The case has rattled the Chinese community in the area. The University of Illinois at Urbana-Champaign had more than 5,600 Chinese students enrolled as of last fall, according to university data.

"We just want to seek justice. This is a very special case. We are extremely concerned about the safety and security of the Chinese community," Charlie Li, president of the Chinese American Community of Central Illinois, told the News-Gazette in Urbana on Monday.

Her father and other family members traveled from China to Champaign to join in the search for Zhang.