A car drove into a crowd of people in Berlin on Wednesday, killing one person and leaving five with life-threatening injuries, a fire service spokesperson said.
More than a dozen people were injured, a police spokesperson at the scene in western Berlin said, next to the war-ravaged Kaiser Wilhelm Memorial Church, one of German capital's best-known landmarks.
"A man is believed to have driven into a group of people. It is not yet known whether it was an accident or a deliberate act," police said, adding that bystanders had detained him at the scene before handing him over to authorities.
"We are currently on the scene with about 130 emergency personnel," the police added. "The vehicle, a small car, was secured on site."
Investigators were looking into whether the incident was a deliberate attack or possibly an accident with a medical cause, a police spokesperson said.
Police were investigating all possibilities, the spokesperson said, adding that the driver had received some medical treatment.
The site, on a shopping street near a McDonald's restaurant, was cordoned off.
The incident took place near the scene of a fatal attack on December 19, 2016, when Anis Amri, a failed Tunisian asylum seeker, hijacked a truck, killed the driver and then ploughed it into a crowded western Berlin Christmas market, killing 11 more people and injuring dozens of others.
Amri then fled to Italy, where Italian police shot him dead.