A new round of threats against Jewish community centers across the United States forced the facilities to be placed on lockdown or evacuated on Tuesday, the groups said, and all 100 US senators asked the federal government to help them enhance security.
Threats were phoned in or emailed to JCCs in states including New York, Wisconsin, Illinois and Florida overnight and early on Tuesday.
Federal authorities have been investigating a surge of threats against Jewish organizations, including more than 100 hoax bomb threats in five separate waves in January and February against JCCs in dozens of states.
A Jewish school, daycare and community center was evacuated also in Toronto, after receiving a bomb threat.
Tuesday’s incidents appeared to be unconnected to the majority of previous threats, according to the Secure Community Network, which provides security expertise to Jewish groups.
“Bomb threats tactics are evolving; copycats incidents appear to be on the rise,” the company said on Twitter.
A letter signed by all 100 US senators was sent on Tuesday to Homeland Security Secretary John Kelly, Attorney General Jeff Sessions and FBI Director James Comey requesting they assist Jewish groups to enhance security.
“We are concerned that the number of incidents is accelerating and failure to address and deter these threats will place innocent people at risk and threaten the financial viability of JCCs,” the letter said.
The Federal Bureau of Investigation, which is leading the nationwide probe, was not immediately available for comment.
One arrest was made last week, when former journalist converted to Islam Juan Thompson, 31, was charged in St. Louis with using fake email accounts to threaten to bomb Jewish sites while posing as his ex-girlfriend. But he is not believed to be responsible for the majority of threats.
In Chicago on Tuesday, police responded to a called-in bomb threat at a private Jewish day school at around 9:10 am, according to department spokeswoman Michelle Tannehill.
Following an evacuation, the school was declared safe by police and students were allowed to return, Tannehill said.
Other targeted institutions included the Louis S. Wolk Jewish Community Center near Rochester and the Jewish Community Center of Syracuse, both in upstate New York; the Harry and Rose Samson Family Jewish Community Center in Milwaukee; and the day school of the David Posnack Jewish Community Center in Davie, Florida.
There has also been a rash of vandalism at Jewish cemeteries since early January.
The Anti-Defamation League, a Jewish civil rights organization, also said it received bomb threats at multiple locations.
“Law enforcement personnel are responding,” the group said on Twitter.