A male white wearing a mask entered the bank demanding money and then fled on foot. The offender fled to the intersection of Montrose and Saylor and entered a white or silver SUV that was waiting at the intersection, according to the news release.
Witnesses told police that a dye pack exploded, "possibly contaminating the offender as he entered the vehicle," according to the press release.
Several schools were placed on lock-down while police conducted a search of the area. The schools notified were Lincoln Elementary School, Bryan Middle School, Madison School and Jackson Elementary School.
Agents from the FBI are currently on the scene and will be the lead agency handling the investigation in cooperation with the Elmhurst Police Department.
Patch.com will update with more information as it becomes available.