About 12,000 people were evacuated Thursday from Potsdam as explosives experts removed an unexploded World War II bomb from the Brandenburg state capital. The city center, including the main train station and Brandenburg state government offices, was sealed off for about 4 1/2 hours as the 550-pound American bomb was defused and removed.

The bomb was found Tuesday on a construction site in the city, the former residence of Prussian kings just outside Berlin.

It is not unusual for crews to find unexploded bombs, relics of Soviet and Allied bombardments before Germany's official surrender in May 1945.

Potsdam had escaped the war relatively unscathed until an Allied bombing raid on April 14, 1945, destroyed much of the city.

The bomb was the fourth found in the vicinity in the past two years.

CoutryWatch: Germany