Man who allegedly threatened Jewish community told FBI he dislikes Jews: Sources

A young man who allegedly posted a threat online against the Jewish community in New Jersey told the FBI he is angry and dislikes Jewish people, but had no plans to do anything harmful, sources told ABC News.

The FBI on Thursday announced the "broad threat" to New Jersey synagogues on Twitter and urged people to "stay alert" and "take all security precautions."

On Friday, the FBI said it identified the "source of the threat" made against "an unspecified New Jersey area synagogue." The person "no longer poses a danger to the community," the FBI said.

According to sources, the young man had posted on a social media site that's frequently used for antisemitic discussion.

His post was written as if an attack had already occurred and in a style used by mass shooters, which raised the level of concern and triggered the FBI's tweet out of an abundance of caution, sources said.

Once the young man was located, authorities realized there was no threat, sources said, though they are continuing to look into his background.

When the FBI's warning was announced on Thursday, New Jersey Attorney General Matthew Platkin said law enforcement would increase patrols.

"Some of these patrols will be in marked vehicles and others will not -- but please do not be alarmed if you observe an increase in police presence as we are taking these steps in an abundance of caution," Platkin said in a statement.

Platkin also urged residents "to be extra vigilant" and report any suspicious activity to the police.

New Jersey Gov. Phil Murphy tweeted Thursday, "We are closely monitoring the situation and are working with local law enforcement to ensure that all houses of worship are protected."

New York City Mayor Eric Adams and NYPD Commissioner Keechant Sewell are meeting virtually Friday with Jewish leaders to discuss recent threats and to outline precautions New York City is taking to ensure the safety of Jewish community.

"As of now there are no credible threats against synagogues in New York City, but out of an abundance of caution you will see increased police presence in our Jewish community and at houses of worship," Adams said. "The insidious rise of blatant anti-Semitism in recent years, with vicious lies and hate spread by voices of bigotry and intolerance, must never be ignored. It must be confronted. We will keep our Jewish community safe."