All three devices were discovered Thursday morning.
One device was found on an ATM at a convenience store in the 400-block of West Armitage Avenue in the city's Lincoln Park neighborhood.
The second device was found in the 100-block of North Clinton Street in the city's West Loop neighborhood.
The third device was found in the 600-block of South Clark Street in the city's South Loop neighborhood.
Investigations into all three devices are ongoing, police said.