A man has been shot dead by officers during a police operation in the northern German port city of Hamburg.
The unknown man had previously stopped cars, damaged them and threatened the drivers with a knife on Friday, police spokeswoman Sandra Levgruen said.
Police officers who were alerted first used pepper spray while special commando officers who happened to arrive at the scene used a Taser.
Neither had any effect.
The man continued to approach the officers with the knife in his hand and was then shot at.
The attacker was seriously injured and died a short time later despite the intervention of an emergency doctor.
"It is still unclear exactly how many times and by whom shots were fired," Levgruen said.
According to several witnesses, the man had shouted "Allahu akbar!" or "God is greatest" in Arabic, the police spokeswoman said.
An extremist motivation for his behaviour could not be ruled out, which is why, in addition to the homicide squad, the State Protection Department of the State Criminal Police Office was also involved in the investigation.
As is always the case when police officers use their service weapons, the Department of Internal Investigations (DIE) is also involved in the investigation.
The scene of the incident, which had been cordoned off, was to be examined in the evening in order to reconstruct the course of events.
Apart from the fatally injured man, whose identity was not initially known, no one was injured, according the police spokeswoman.
Several cars were damaged by him.