Germany says half of far right 'prone to violence'
Some 12,700 far-right Germans are prepared to commit violence, of an estimated 24,000 far-right extremists, according to interior ministry figures.
Authorities had already warned of a growing threat of violence from the extreme right, including an "affinity for weapons", the ministry said.
Hundreds of flag-waving extremists caused alarm this week when they marched through an eastern town.
Germany's main Jewish organisation said the march should not have been allowed.
The marchers carried a banner that read "social justice instead of criminal foreigners". They carried flares and banged drums through the centre of Plauen, a town in Saxony whose synagogue was burnt down by the Nazis in November 1938.
The Saxony march took place on Wednesday, on the eve of Jewish remembrance of the Holocaust. Leaders of the left-wing Linke party in Saxony said they were appalled that "uniformed Nazis were allowed to march with torches and drums".