The Federal Bureau of Investigation said the nationwide swatting spree targeting Jewish institutions last week likely was coordinated by an entity outside the United States.
In a confidential memo obtained by ABC News, Assistant FBI Director Cathy Milhoan told local law enforcement that "similar language and specific email tradecraft" indicate the incidents were connected.
"Additionally, these threats appear to be originating from outside of the United States," Milhoan said of the record 199 swatting incidents and false bomb threats targeting Jewish facilities.
"The safety of all faith-based communities is one of the FBI's highest priorities. Once again, thank you for your partnership and your collaboration to keep our communities safe," Milhoan added.
The Secure Community Network first reported on the spike in "swatting" — a dangerous practice in which someone prank calls a threat to mobilize swat teams — against Jewish facilities on Friday and Saturday.
Broken down further, the SCN found that 93 of the incidents hit Jewish facilities in California, 62 in Arizona, 15 in Connecticut, five in Colorado, and four in Washington. Other states were also targeted.
SCN, a nonprofit focused on the safety and security of Jewish Americans, said the occurrences compared to last year have gone up 541% to over 449 logged swatting incidents and bomb threats against Jews.
"We continue to work in coordination with law enforcement and Jewish security partners to respond to incidents & ensure Jewish communities across North America have the tools and guidance to respond appropriately," SCN stated.
The news comes amid a wave of anti-Jewish hate stemming from the terrorist group Hamas' deadly Oct. 7 attack in southern Israel and the subsequent war over Gaza.
Still, the Anti-Defamation League recorded a spike in "online trolls" targeting U.S.-based synagogues dating to August.
"The trolls use highly antisemitic language in these calls" and "appear to be targeting synagogues that livestream their services," ADL CEO and National Director Jonathan A. Greenblatt said at the time.