Cheboygan, MI — The FBI is seeking information on two explosive devices found outside cellphone stores in northern Michigan. The bombs, which were defused, were found in suspicious packages left outside a Verizon store in Cheboygan and an AT&T store in Sault Ste. Marie. Cheboygan authorities say emergency personal were dispatched around 9 a.m. Thursday after an employee reported a suspicious package near the door of the business. A similar device was reported the same day in Sault St. Marie. The FBI and Michigan State Police believe the devices are related to a series of letters discovered in the Upper Peninsula last month.