Authorities are investigating a suspicious package that was dropped off Wednesday at a post office in Lake View on the North Side.
A female suspect entered the post office at 9:27 a.m. in the 1300 block of West Irving Park Road and dropped an envelope on the counter with the words "notify the FBI" written on it, according to Officer Jessica Rocco, a Chicago police spokeswoman.
She then ran away, Rocco said. The CPD Bomb and Arson unit has been called to the scene to investigate.
Irving Park Road was closed between Clark Street and Southport Avenue.
The Chicago Fire Department is also responding to the scene for reports of a hazardous materials situation, spokesman Larry Merritt said.