(JTA) — Jihadists arrested last year in Lyon were planning to carry out a terrorist attack at a Jewish group’s conference about anti-Semitism, a French newspaper reported.

The five suspects who were arrested in a series of sweeps by French police between Sept. 16 and Sept. 18 were planning to strike on Sept. 18 at an event organized in Lyon by the regional branch of the CRIF umbrella of French Jewish communities and organizations, according to a report Tuesday in the Le Progres daily.

An unnamed police officer who is in charge of the investigation confirmed to the daily that the suspects were arrested following the interception of a Sept. 5 telephone conversation in which they discussed their plans.

Among the five arrested are Karim and Reda Bekhaled, brothers who are believed to have been involved in recruiting radical Muslims to fight in Syria, along with the remaining three suspects. Reda Bekhaled was heard discussing the plans in the recorded conversation.

The police officer said the brothers “had the ambition of dying as martyrs” and “planned to carry out imminently an act of violence.”

On Jan. 9, Amedy Coulibaly, another suspected jihadist, killed four people at a kosher supermarket outside Paris where he held 19 people hostage for several hours before police stormed the building and killed him. The attack was part of a string of terrorist acts committed by Coulibaly and two accomplices who on Jan. 7 murdered 12 at the offices of Charlie Hebdo weekly for its ridicule of Islam.

Coulibaly and the two brothers were part of a cell that also recruited jihadists to fight in Syria, French police said.