A Paris court Friday sentenced to prison four men from a French neo-Nazi group who discussed attacks on mosques and Jewish targets in an online chat group.

A 27-year-old former voluntary police officer accused of being the ringleader received 18 years in jail, the longest term, with the judge concluding he had “an undeniable influence over the group.”

The man, Alexandre Gilet, was arrested after police learned he had ordered equipment that could be used for making explosives and was found in possession of weapons, including two Kalashnikov machine guns.

The other three men, one of whom was a minor at the time, were given lighter prison terms ranging from five to three years. They are expected to serve non-custodial sentences.

Prosecutors alleged during the trial that the four men, now aged between 22 and 28, joined a private internet chat group called “Operation WaffenKraft”, where talks “very quickly turned to the preparation of terrorist projects”.

The Waffen-SS was the military branch of the Nazi’s elite SS corps, which was founded by Adolf Hitler.

The chat group discussed targets, including mosques as well as the headquarters of the Jewish council (CRIF) and the office of the anti-Jewish discrimination league (LICRA).