U.S. prosecutors in New York have charged a St. Louis, Mo., man in connection with at least eight bomb threats against Jewish organizations across the country.

Juan Thompson, 31, was taken into custody Friday morning in St. Louis and was expected to make an initial court appearance later in the day.

It was not immediately clear whether investigators believe Thompson is responsible for all of the more than 100 threats that have been made by phone to Jewish community centres in dozens of states since January.

In a criminal complaint filed in federal court in Manhattan, authorities accused Thompson of making at least eight threats, mostly by email.

Prosecutors said Thompson made the threats in an effort to harass a former girlfriend by telling the Jewish groups she was the person behind the alleged bombs.

Jewish community centres and schools in the United States have received five waves of hoax bomb threats this year, stoking fears of a resurgence in anti-Semitism.

Suspect was former reporter

Thompson was a reporter for the Intercept, a news website focused on national security, until he was fired last year after the site found he had invented sources and quotes. In a statement, Intercept editor Betsy Reed said the website was "horrified" by the allegations but that she had no more information.

Announcing his dismissal in February 2016, the Intercept said Thompson created a fake email account to hide his fabrications. Months later, prosecutors said, Thompson used the same technique to perpetrate his fake bomb threats.

After the woman broke up with him in July 2016, Thompson began a sustained harassment campaign in retaliation, authorities said. A day after the relationship ended, Thompson sent an email purporting to be from a producer at a national news organization to her boss at a social service company in New York, according to the complaint. The email claimed she had been pulled over for drunk driving and sued for spreading a sexually transmitted disease.

In the following weeks, the woman received messages from a purported relative of Thompson, falsely claiming Thompson was on his deathbed after a shooting, the complaint says. Thompson later threatened to publicize nude photos of her and told her employer she had threatened his life, prosecutors said. He also sent a message to a national children's welfare organization, claiming she admitted watching child pornography, according to the complaint.

Suspect on Anti-Defamation League's 'radar'

In late January, Thompson began emailing bomb threats to Jewish groups using his own name and claiming she had hacked his account. He also sent threats pretending to be her, according to the complaint.

On Feb. 24, he posted on Twitter, "Know any good lawyers? Need to stop this nasty/racist #whitegirl I dated who sent a bomb threat in my name."

Prosecutors said part of his motive was to portray his ex-girlfriend as an anti-Semite. He sent one email calling for a "Jewish Newtown," referring to the 2012 school massacre in Connecticut.

It was unclear whether he shared those sentiments and his recent Twitter posts did not appear to include any explicit anti-Semitic thoughts. But the Anti-Defamation League, which received one of Thompson's threats, said he had been "on the radar" due to his past activities, including his Intercept work and his "rants against white people."

Thompson was due to appear in Federal Court in St. Louis later Friday. It was not clear whether he had a lawyer. He is charged with one count of cyberstalking. The ex-girlfriend could not be reached for comment.

Cemeteries vandalized

Dozens of headstones trashed; part of wave of anti-Semitic incidents 0:26

U.S. President Donald Trump, Israeli officials and Jewish groups have all condemned the surge in intimidation as well as cases of vandalism targeting Jewish cemeteries. Police said last weekend that about 100 headstones were toppled at a Jewish cemetery in Philadelphia, about a week after a Jewish cemetery in St. Louis was vandalized.

Some Jewish groups see the vandalism and threats as a sign that anti-Semitic groups have been emboldened by Trump's election. His campaign last year drew the support of white supremacists and other right-wing groups, despite Trump's disavowals of them.