Police are investigating after they received a report of abusive messages having been sent to the Belfast Jewish Community.
The messages were posted on their Facebook page and have since been passed to the PSNI.
Rabbi David Singer said they are now reviewing their security measures.
Posting on their page, the community said it was with a “heavy heart and great sadness” that they had to inform members about the incident.
It said: “Until further notice we cannot put up times, dates and locations of events to do with the Belfast Jewish Community.
A few days ago a message was sent to ourselves which was vile, hateful and very anti-Semitic.
“It was fortunate that we filter all our messages before they reach the main page.
“We are currently reviewing our security measures as a result of this.”
Speaking to the Belfast Telegraph, Rabbi Singer said: “It’s no secret that in the past four years this isn’t the first time we’ve had to report a hate crime.
“But I think it’s fair to say that there are crazy people doing crazy things all the time about different issues.
He added: “I don’t read too much into this.”
Mr Singer said it would “certainly not” deter their work and meetings.
A PSNI spokeswoman said: “Police have received a complaint regarding abusive messages posted on social media on Wednesday, February 15.
“Enquiries are continuing into the matter.”
On August 13 last year graves at Belfast City Cemetery were destroyed in an anti-Semitic attack. Work has been undertaken to restore the Jewish plot, which dates back to 1871.
The Jewish community in Northern Ireland numbers around 80 people.
UUP politician Robert Foster said he condemned the “disgraceful threat” in the strongest possible terms.
“Any such threats must be taken seriously bearing in mind the terror attacks which have taken place in Europe, often targeting the Jewish community,” he said.
“Furthermore, thirteen Jewish graves were damaged in an attack at the City Cemetery in August, and I believe it is vital that public representatives should speak out in condemnation of all these type of incidents.
“This is a community which has a long and proud history in Northern Ireland and especially in the city of Belfast. It has been prominent in the cultural, political and business life of the city, providing Lord Mayors and leading industrialists.
Indeed one President of Israel Chaim Herzog was born in Belfast in 1918.
“I believe we must recognise the very positive role the Jewish community has played and still plays in Northern Ireland and provide support at times like this.”