CHICAGO (AP) -- Federal authorities are investigating what appear to be death threats against several politicians, including Republican Bobby Schilling of Illinois.

U.S. Capitol Police Sgt. Kimberly Schneider confirmed Thursday that the agency is investigating a death threat against several congressmen but declined to give any further details. She cites an ongoing investigation.

Schilling spokeswoman Andie Pivarunas says the congressman received a "very concerning email alert" on Tuesday and alerted authorities. She says Schilling and his family are taking precautions while authorities investigate.

She declined to give details.

FBI spokesman Jason Pack says the FBI is aware of the threat and is investigating. He declined to give further information.

Schilling won Illinois' 17th district last year, a once reliably Democratic district covering a wide portion of the state's western border.