The city hall in Goettingen was evauated after an anonymous threat. Fiel picture: Skitterphoto/Pixabay

Munich - City halls in at least six German cities were evacuated early Tuesday due to possible threats of violence, police said.

Multiple cities reported receiving anonymous threats in the mail. A number of the city halls were being searched for possible explosive devices.

The cities of Augsburg, Kaiserslautern, Chemnitz, Goettingen, Neunkirchen and Rendsburg have been impacted, but police said the measures were taken as a precaution and that no concrete threats had so far been found.

A major police effort was underway in Augsburg in southern Germany after the city hall received an anonymous threat.

Goettingen police said they were searching the city hall premises for possible explosives after receiving an anonymous bomb threat. 

Police in Kaiserslautern and Neunkirchen also reported receiving bomb threats and that their city halls had been closed.