The driver reportedly headed for the crowd at 7.20am on Sunday, leaving passers-by “shocked” as he ran over people.
German media outlet BILD News said 55 firefighters had been deployed, along with a rescue helicopter, and police were now on site with explosives and detection dogs.
The outlet also claimed witnesses saw a person needing resuscitation after getting stuck under the car.
The driver was reportedly arrested after being detained by security officers at the scene.
Police say there is currently no evidence that the incident is politically or religiously motivated.
An investigation is underway.