A man has taken several people hostage in the townhall of Ingolstadt, just hours before Chancellor Angela Merkel was due to hold a speech in front of the building in the southern German city, police said.
Police added the man said he was armed, and they were in contact with him by telephone, although he had not yet made any demands.
There was no sign of a connection with Merkel's visit, they added.
Authorities evacuated the building and closed off part of the town.