The child care center operated by the Library of Congress will be closed Thursday because of an anonymous New Year’s Eve voice mail that threatened a bombing on Jan. 5.

Though the Capitol Police and the FBI don’t consider the threat credible, the center’s director said in an email obtained by Roll Call that the center would be shuttered for the day because so many staffers said they were afraid to come to work in light of the threat.

Little Scholars Child Development Center Director Ilene Lewis informed parents Wednesday afternoon that the center would be closed Thursday.

“Despite all assurances from law enforcement” that the bomb threat was not credible, Lewis wrote, “enough staff said they will not be coming to work tomorrow out of concern … such that keeping the center open tomorrow is not viable.”

James Smith, an assistant U.S. attorney for the District of Columbia, laid out the chronology of events in an email Lewis forwarded to parents. On Dec. 31, when Little Scholars was closed for the holidays, someone left a voice mail message stating that on Jan. 5, “a bomb would be placed at ‘your day care.’” When the center reopened Tuesday and Lewis heard the message, she immediately informed Capitol Police.

During the past 24 hours, Capitol Police involved the FBI, and both agencies have investigated the matter. According to an update Tuesday from Lewis, Capitol Police will be coming to the center every morning throughout this week for a sweep of the building with the help of bomb-sniffing dogs.

She said neither entity said the threat was serious and did not recommend closing the center Thursday.

“We regret the fact that we have to make the decision to close,” she wrote Wednesday. “We have been pleased with the response from law enforcement and agree with their assessment that this is not a credible threat.”

Capitol Police spokeswoman Sgt. Kimberly Schneider would not elaborate on the force’s involvement and findings, telling Roll Call that “we’ve put temporary security measures in place, but nothing hazardous has been found.”

Little Scholars, which opened in 1993, provides day care services for the children of employees of the Library of Congress, legislative branch offices, federal agencies and community members.