The man waved the sword toward the head of a 24-year-old man who was passing by. The sword stopped just inches from the passerby's head, while the man verbally threatened the passerby.
Witnesses identified the sword-wielding man and informed police. The man also had an axe standing next to the door of his apartment and the police also learned that he kept a fighting dog in his apartment.
The police sent a special commando unit to arrest the man. Two other men who were in the man's apartment were also briefly detained before being released after authorities determined they had not been involved in the threats.
According to police, the 25-year-old was taken to a psychiatric clinic for examination.
Police found a collection of "chopping and stabbing weapons" in the man's apartment, which they secured.
Saturday's incident is the latest in a string of bizarre sword attacks in Germany. In June 2008, a drunken man attacked police with a samurai sword in Berlin, and in October of the same year, a retired man was arrested in Berlin after attacking a neighbour with a samurai sword.