Authorities are investigating a "credible" threat at a plant in Peoria, Illinois, after a device was discovered at the facility Friday night and later rendered safe by bomb technicians.
No additional devices were found and the evacuation order within a one-mile blast radius of the BioUrja Renewables facility has been lifted after investigators searched the facility for hours, Peoria police said Saturday.
Police determined at about 6:45 p.m. local time Friday that a package at the facility was a credible threat and established a one-mile blast radius, officials said.
Bomb technicians "rendered the package safe" at about 9:12 p.m. local time, according to police.
A law enforcement source told ABC News Saturday the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and FBI are leading an investigation, and it is criminal in nature.
ATF special agents were on the scene clearing the building, the source said.
Asked about the device found Friday night, Police Chief Brad Dixon said he would not discuss that further, explaining that it is "part of the criminal investigation."
Dixon said he could not say "what type of device it was."
Officials had said they were not treating the incident as a hoax.
"When a bomb threat comes in, typically, it's not legitimate, and they're doing it to cause an evacuation of a building or something like that," Dixon said at a press conference late Friday. "This is not the case here. We found a credible package that we deem to be a threat. This is ... this is not. We're not considering this a hoax."
Authorities had closed most streets in the area Friday night and urged the public to avoid the one-mile radius around the facility until further notice.
Approximately 60 to 80 people were at the designated "shelter place" -- a high school -- Dixon said earlier. Officials conducted door-to-door notifications in the entire radius.
Asked if the incident was being investigated as a terrorist threat, Dixon said that officials would not comment on the criminal investigation as it is "active" and "open."
The police chief explained the search was difficult due to the facility's size, describing it as large as 44 1/2 football fields.
Chris Amon of the ATF Chicago Field Division said that the agency "and our partners remain committed to finding the person or persons responsible for this criminal act and ensuring that they are held fully accountable for their actions."
“To date, our office has provided investigative bomb technician and intelligence resources toward this collective effort," Ryan Presley, special agent-in-charge of the FBI Springfield Field Office, said.
Illinois Gov. JB Pritzker said on social media he was "actively monitoring the bomb threat in Peoria, and I have directed the Illinois State Police to coordinate with local authorities." He urged residents to follow directions from police and stay away from the evacuated area.
Country music singer Jon Pardi's concert in Peoria was also canceled because of its proximity to the bomb threat.
Pardi posted a message to his Instagram followers Friday night, saying, "Peoria, we're disappointed that we won't get to spend tonight with you, but the safety of our fans, our team and the community is always the priority. At the discretion of the Chief of Police, tonight's concert has been canceled due to an active local safety concern. Thank you for your understanding, and stay safe."
-ABC News' Luke Barr contributed to this report.