Firefighters and Bomb and Arson Unit personnel respond to a report of a suspicious package near 18th and Ashland on Monday afternoon.
The threat of a suspicious device found in a trash can in the city's southwest side Pilsen neighborhood was "eliminated," a police source told NBC Chicago.
The report of a package left in the 1600 block of West 18th Place was received shortly before 3:30 p.m. said police spokesman Veejay Zala. The area is near Peter Cooper Public School.
"It's some kind of device that looks like a bomb," a law enforcement source close the investigation told NBC Chicago, adding that it is "about the size of dynamite."
"It's enough to make [the Bomb and Arson Unit] treat it seriously," the source said.
The sound of an explosion was heard as authorities responded. NBC Chicago is told authorities fired a "disrupter" at the device to see if it explodes.
Traffic was diverted in the area and a few area buildings were evacuated, officials said.