DENVER — The Denver Public Library closed all locations and canceled Bookmobile stops on Wednesday after it received what it called an unspecified threat overnight.
All locations except those closed for renovations or maintenance reopened on their normal schedules on Thursday.
The Denver Police Department said Wednesday afternoon that preliminary findings indicate the threat was sent from out of state and that a number of similar threats were sent to libraries in other states.
As a precaution, officers will do extra patrols around Denver Public Library locations, police said.
"We take all threats seriously and prioritize the safety of our staff and customers," according to a statement Thursday on the library system's website. "We continue to work with local law enforcement and city partners to investigate the digital threat."
Denver Public Library, which has 27 branches across the city, provides community services and public access to computers and technology, in addition to books and other media.
Unspecified threats have also caused disruptions this week for schools in the metro area. The FBI Denver Field Office said it was working with local law enforcement to investigate "swatting" incidents on Monday.
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