Another round of threats against Jewish community institutions across the United States forced the facilities to be evacuated on Tuesday, the groups said.
Threats were phoned in or emailed to JCCs in New York, Wisconsin and Florida overnight and early on Tuesday.
The threats have continued even after a federal investigation of phoned and emailed threats against Jewish groups across the nation yielded an arrest last week. Former journalist Juan Thompson, 31, was charged in St. Louis on Friday with using fake email accounts to make bomb threats against Jewish groups while posing as his ex-girlfriend.
U.S. authorities said they were examining more than 100 threats made against Jewish community centers by phone this year, which appear unrelated to the Thompson allegations.
In the latest threats, the Louis S. Wolk Jewish Community Center near Rochester, in upstate New York, received an emailed bomb threat, Brighton Police Chief Mark Henderson told reporters.
The Harry and Rose Samson Family Jewish Community Center in Milwaukee and the David Posnack Jewish Community Center in Davie, Florida, were also targets.
The Anti-Defamation League, a Jewish civil rights organization, also said it received bomb threats at multiple locations.