A fringe meeting at the Labour party conference was halted and a building evacuated after a bomb hoax on Tuesday evening.
Police were called to a meeting in Liverpool showing a film screening organised by Jewish Voice for Labour.
A man called and said: “There are two bombs that will kill many people.”
Other groups in the building had to leave, including pilates and teacher training students.
The film being shown by JVL, attempts to show how the antisemitism row is used to censor pro-Palestinian support for Labour leader Jeremy Corbyn – a narrative strongly disputed by the mainstream Jewish community and other Labour members.
The Board of Deputies tweeted: “We utterly condemn the antisemitic bomb threat made to those attending a fringe event at the Labour conference. We hope the perpetrators of this racist act will be found & prosecuted. This latest threat underscores the need for all parties to take antisemitism seriously.”