(WXYZ) — The FBI is searching for a suspect or suspects who allegedly left explosive devices outside of cellphone stores in two Northern Michigan cities.
According to the FBI, the explosive devices were found on Thursday outside of stores in Sault Ste. Marie and Cheboygan.
Police and bomb technicians arrived and rendered the devices safe.
According to the FBI, the devices were contained inside USPS Priority Mail boxes, sealed with black duct tape and had threatening notes that were signed either "HJ" or "Handcuff Johnny" and the letters "CMT" were written on each box.
They are reminding people not to touch, move or handle any suspicious packages.
The FBI believes the devices are related to a series of letters discovered in the U.P. last month that claimed to be from the "Coalition for Moral Telecommunications" that were found at towers throughout the UP.
The FBI is asking anyone with information to call them at 1-800-CALL-FBI or submit tips at tips.fbi.gov.