The police station at Northern Illinois University was locked down on Wednesday morning as special agents from the FBI and state police served a search warrant there.

The FBI is the lead investigating agency in the incident, and is operating in conjunction with the U.S. Department of Education's Office of the Inspector General, and the Housing and Urban Development's Office of Inspector General, officials said. The search began about 8 a.m., authorities said.

Illinois State Police were on the scene with a mobile command unit, and law enforcement officers were seen taking items out of the building and into the vehicle.