Germany's extremist "Reich Citizen" and "Selbstverwalter" sovereign citizen movements are rapidly growing and its members are prepared to commit "the most serious acts of violence," according to a report from the Bild newspaper.

"Reich Citizens" and "Selbstverwalter" refer to a loose grouping of people in Germany who do not recognize the authority of the current system of government. There is no unified structure and several groups use the names despite very different belief systems.

There are currently 16,500 people active in the scene – up from 12,800 in 2016, Bild reported, citing a report that was presented yesterday in Berlin by Interior Minister Horst Seehofer and domestic intelligence chief Hans-Georg Maassen.

Three quarters of the movement are men above the age of 40 and some 900 members of the scene are right-wing extremists, up from 800 in 2016, according to the article in Bild's Tuesday edition.

According to the intelligence report, the movement has been marked by militancy and has a "high affinity for weapons," and both "Reich Citizens" and "Selbstverwalter" are "prepared to use their weapons for the most serious acts of violence."

The domestic security agency (Verfassungsschutz) therefore categorizes members of such groups as "anti-government and extremist," according to the newspaper. German authorities are increasingly concerned over growing right-wing terrorism in the country. Since 2016, Germany has conducted an increasing number of nationwide raids targeting right-wing groups, including houses, apartments and other properties believed to be owned by members of such groups, targeting the so-called Reich citizens movement, Reichsbürgers.

The far-right extremist group is considered a terrorist organization in Germany where its members procure arms and ammunition. Reichsbürger members do not recognize the modern German state as legitimate, citing technicalities about the fall of the Nazi Third Reich in May 1945, stipulating that while the Wehrmacht top brass did surrender to the Allies, the political leaders of the government, such as ministers and Adolf Hitler himself, never surrendered. Hitler also considered the surrender of Heinrich Himmler and Hermann Göring as high treason, expelling them from the government before the Reich's collapse. The far-right movement also believes that the legitimate borders of Germany are those of 1937, before the annexation of Austria and the Sudetenland. They also refuse to acknowledge the modern constitution and pay no taxes, claiming to be following the laws of the Third Reich's constitution.