A man wielding a machete killed a woman and wounded two other people in the southern German city of Reutlingen on Sunday before being arrested, police said.
A statement said the suspect was a 21-year-old asylum seeker from Syria who was previously known to police.
Police said there was no indication that the attack was motivated by terrorism.
They added the knifeman appeared to be a "lone operator" and that there was no ongoing threat to people in the city.
The reported incident comes days after a teenager armed with a gun shot dead nine people in the city of Munich before killing himself.
Police in Reutlingen said the knifeman had fatally attacked one women after they got into a quarrel near the city's central bus station at around 4.30pm local time.
He then wounded another woman and a man near to the scene before he was arrested a few minutes later.
It was not immediately clear if he had any personal link to the victims or what the motive might have been.