A driver rammed a car into a crowd Monday in the southwestern German city of Mannheim, killing one person and injuring several others, police said.
A suspect was in custody, police said, later adding that "indications of a second perpetrator cannot be confirmed at this stage of the investigation." They said there was no more danger to the public.
Police would not immediately characterize the incident as an attack. Cars have been used as deadly weapons in several acts of violence in recent months in Germany.
Police spokesperson Stefan Wilhelm said a driver drove into people on Paradeplatz, a pedestrianized street downtown, around noon, when workers come for lunch breaks. Local media reported a carnival market was taking place, meaning more visitors than usual in Mannheim, with a population of 326,000.
Mannheim University Hospital said they were treating three people from the crash, two adults and a child, German news agency dpa reported. It was not immediately clear whether other hospitals received patients.
Images from the scene showed parts of the downtown area cordoned off, with a heavy police presence. Police gathered round a badly damaged black car.
Last month, a 2-year-old girl and her mother died two days after they were injured in a car-ramming attack on a union demonstration in Munich. A 24-year-old Afghan man who came to Germany as an asylum-seeker was arrested, and prosecutors said he appeared to have an Islamic extremist motive.
Last year, six people were killed and more than 200 injured when a car slammed into a Christmas market in the eastern city of Magdeburg. The suspect, who was arrested, is a 50-year-old doctor originally from Saudi Arabia who had expressed anti-Muslim views and support for the far-right, anti-immigrant Alternative For Germany party.