Some 3,000 residents in the German city of Potsdam on the outskirts of Berlin have to leave their homes on Friday while a World War II bomb is disposed of, spokesperson for the city said.

The 800-metre-radius exclusion zone around the site where the bomb was discovered in the city centre also takes in regional government buildings and the federal German police headquarters.

During the bomb disposal, trains, buses and trams are to be suspended between Potsdam central station and the district of Babelsberg, home of the German film industry

The spokesperson said the unexploded 250-kilogram device is buried 60 centimetres in the ground and is slightly deformed, possibly requiring the disposal experts to explode it in situ, depending on its condition.

Some 200 city workers, fire service men and police officers are expected to take part in the evacuation.