A new wave of threats were made against Jewish institutions on Tuesday, including one to the Anti-Defamation League headquarters in New York City, officials said. 

Speaking at a news conference at a Staten Island Jewish community center, NYPD Chief of Detectives Robert Boyce said there was an active investigation at the ADL headquarters on Third Avenue in Manhattan.

The caller electronically disguised his or her voice and “spoofed” the originating phone number to appear as if the call was originating from inside the organization, said Etzion Neuer, a regional ADL deputy director.

“The call came in, threatened an explosive device that was lethal and there was a time period given in which people were told they had to evacuated,” Neuer said.

ADL offices in Boston, Washington D.C. and Atlanta also received threats, the NYPD said. Additionally, JCCs in New York, Wisconsin, Illinois and Florida were targets of phoned in or emailed threats.

​NYPD Commissioner James O’Neill said there has been a 113 percent increase in hate crimes in 2017, compared with the same time period in 2016. Anti-Semitic hate crimes have seen a particular increase he said, with 45 incidents in 2017 so far, compared with 19 in the same period in 2016. 

Mayor Bill de Blasio said there hasn't been such a concentrated number of threats on the Jewish community in years, and the city is not taking them lightly.

“We have not seen anything like this in many years,” de Blasio said. “We’re really in an unprecedented moment.”

He added that “an attack on one community is an attack on all communities.”

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 letter signed by all 100 U.S. 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.

One arrest was made last week, when former journalist Juan Thompson, 31, was taken ino custody in St. Louis and charged with allegedly 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.

Boyce said the NYPD holds Thompson responsible for two threats in the city, one on Jan. 28 to a Jewish museum and one on Feb. 22 to the ADL headquarters.

“The two JCC cases are still open," he said, adding that the department is working with the FBI to catch those responsible.

In Chicago on Tuesday, police responded to a called-in bomb threat at a private Jewish day school at around 9:10 a.m., 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.

-With Reuters and Matthew Chayes