Two men, 30 and 33-years-old, are alleged to have committed arson attacks and to have threatened competitors of a convicted boss of a prostitution network at his behest. Both pleaded guilty in some cases.
The trial is taking place under strict security measures.
Seven men from "Objekt 21" were found guilty of Nazi revivalism in a previous trial, and all were sentenced to jail. The jail terms ranged from an 18 months suspended sentence to six years.
According to reports from the courtroom, one defendant has covered his tattoos of right-wing extremist symbols with tape.
The trial is scheduled to last nine days and the verdict is expected to be announced on August 20th.