The Chicago Tribune reports that “U.S. military personnel are conducting training exercises in and around Chicago through Thursday, including flying military helicopters in areas around downtown at night.”

“City agencies are providing support for the “routine military training exercises,” according to a release from the city’s Office of Emergency Management and Communications.”

“Monday night, many Chicagoans wondered what military helicopters were doing downtown. They are part of the training exercises, a spokeswoman for the office said.”