Violent clashes erupted in Berlin on Thursday night after a 37-year-old man was stabbed to death in a dispute over a parking space.
The suspected perpetrator was arrested on Thursday evening, police in the German capital said, after the incident in the northern neighbourhood of Gesundbrunnen.
The victim was stabbed in the stomach in the attack, which occurred at around 6 pm (1600 GMT), and died in hospital.
A homicide squad has taken over the investigation.
The incident took place after several men argued over a parking space on Böttgerstraße.
The incident involved the 29-year-old suspect, of German-Turkish nationality, and the victim, from Cameroon
Police reported violent scenes at around 11 pm after the victim's relatives and acquaintances gathered at the scene of the stabbing.
An estimated 30 to 40 people tried to enter the cordoned-off crime scene and behaved aggressively with police. Five officers were lightly injured after bottles were thrown at police.
Photos from the B.Z. newspaper showed protesters being pushed and carried away by police.
The police union said: "Anyone who carries a knife is prepared to seriously injure or even kill others."
The union said it was understandable that relatives of the victim reacted emotionally, but police actions cannot be hindered and officers should not have to face bottles and stones being thrown at them.