Germany's domestic intelligence service, the Federal Office for the Protection of the Constitution (BfV), has estimated that there are about 18,000 people supporting the far-right Reichsbürger movement — about 80 percent more than in 2016.

A BfV spokesman told Berlin's daily Tagesspiegel that 950 of them were classified as far-right extremists.

Read more: Reichsbürger and neo-Nazis infiltrating Thuringia gun clubs

BfV's 2016 annual report put the number of Reichsbürger, which roughly translates as "Citizens of the Reich," at 10,000, with 500 to 600 of them classified as right-wing extremists.

The term Reichsbürger is used as a label for a loosely connected group that rejects the legitimacy of Germany's government. The movement believes that the 1937 borders of the German Empire still exist and today's government is an administrative construct in a country still occupied by foreign powers. Many subscribe to far-right or anti-Semitic ideologies.

Read more: A guide to Germany's far-right groups

But the steep rise in the reported number of Reichsbürger does not mean that the movement is drawing a similarly large number of new members, according to the BfV. Instead, investigations into the Reichsbürger scene, particularly since a member shot dead a police officer in Bavaria in 2016, have uncovered more people who have held such beliefs for some time but were not previously known to authorities.

The BfV spokesman told Tagesspiegel that about 1,200 supporters of the movement owned licenses to own weapons. The authorities have withdrawn weapon licenses from 450 Reichsbürger since the beginning of 2017.

ap/sms (dpa, AFP, epd)

Each evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.