"Consumers have cited multiple problems, related to unusual accelerations, batteries catching fire, as well as with the remote update system," the regulator said.
In October, it was forced to recall almost 30,000 cars in China because of problems with their suspension.
There were no immediate reports of casualties and it was not clear if Merkel was inside the building. Dozens of police and a fire engine attended the incident. The driver, who appeared to be in late middle age, was taken away in a wheelchair.