German police raided in 10 German states on Thursday homes linked to an anti-Semitic far-right movement called Reichsbürger, also known as “Citizens of the Reich.”

The Interior Ministry said some 400 police officers seized firearms, neo-Nazi propaganda material and small amounts of drugs when raiding the homes of 21 leading members of the group United German Peoples and Tribes, which is associated with the Reichsbürger movement.

Reichsbürger members, or “Reich citizens,” reject the authority of the modern German state and promote the notion of “natural rights,” along with the ideology of far-right politics and conspiracy theories, according to The Associated Press. The movement is estimated to have 19,000 members in Germany.

The BBC explained that Reichsbürger members “believe in the continued existence of a German empire, or Reich, dating back to 1937 or even earlier. They are Holocaust deniers who espouse racist conspiracy theories.”

“We are dealing with a group that distributes racist and anti-Semitic writings and in doing so systematically poisons our free society,” he said.