Police lifted an evacuation around the BioUrja Renewables ethanol plant in Peoria, Illinois, on November 14 after completing a search of the facility, police said.
The Peoria Police Department said local, state and federal officers found no additional items of concern. Residents were allowed to return home, roads were to reopen and the investigation would continue, the department said.
A device found on November 13 had previously been made safe. Authorities kept the evacuation in place while they searched the property.
The one-mile evacuation zone included parts of Peoria and neighboring East Peoria. Police Chief Brad Dixon had said at an overnight briefing that investigators needed to check the entire property before declaring the area safe.
Mayor Rita Ali described the device as a bomb in remarks reported by NBC affiliate WEEK. Dixon declined to provide details about the number of devices or their locations during that earlier briefing.
The FBI is assisting the investigation, and authorities had not announced any arrests in the latest reporting. The evacuation disrupted events scheduled for November 13, including Jon Pardi's concert at the Peoria Civic Center and the Peoria Chiefs' holiday event at Dozer Park. Pardi said ticket purchases would be refunded.