Several people were injured in an argument between two groups with firearms and stabbing weapons in Dortmund.
There was therefore a large-scale police operation on Sunday, several streets were closed.
Two groups of people clashed on a sidewalk, said a police spokesman on Sunday.
There have also been arrests.
How many injured and arrested there were and what the background to the dispute had is currently being determined.
Dortmund - "The investigations are in full swing."
In the evening the crime scene was examined.
A police spokeswoman said: "We are on site with strong forces." According to the police, there was no longer any danger for the population in the evening.
At the beginning, bystanders were asked to avoid the area around the scene of the incident.
dpa
