BERLIN (AP) — German authorities have indicted eight far-right extremists on suspicion they planned to start a violent uprising.

Federal prosecutors said Friday that they have formally indicted the German men, aged 21 to 31, on suspicion of forming a terrorist organization.

The suspects were arrested last year in eastern Germany's Chemnitz area. They are alleged to have formed a group calling itself "Revolution Chemnitz."

Several of the suspects are alleged to have been involved in an attack on a group of migrants in Chemnitz on Sept. 14.

Authorities intercepted communication between the men indicating that they were trying to obtain firearms.

German officials have warned that far-right extremists pose a serious threat to the country, after a violent neo-Nazi was arrested recently on suspicion of killing a pro-migrant politician.