A man was killed in an attack with a knife in front of a pizzeria in Neustadt am Rübenberge.
A woman was injured in the attack on Friday evening and taken to a hospital, said a spokesman for the Hanover police department.
The alleged perpetrator was overpowered and arrested on site by emergency services.
The "image" had previously reported.
The attacked man was able to save himself after the attack on the street in the pizzeria, but died there.
Photos showed a bloodied car and a bloodstained parking lot in front of the restaurant.
The police are investigating a homicide.
The crime happened at 5:55 p.m., it said.
Further details - such as the identity of victims and perpetrators - and backgrounds were initially unknown.