Nearly one-fifth of people living in the western German city of Koblenz were forced to evacuate their homes on Tuesday to allow authorities to safely defuse a bomb from World War II.
More than 20,000 people were evacuated within a 1-kilometre radius of the find, including residents of a prison and hospital, a city spokesman told dpa.
The 500-kilogram aerial bomb was found on Monday during construction for a kindergarten.
"The area will be sounded out for other explosives so that there does not need to be a second evacuation," the spokesman said.
Koblenz was largely destroyed during the hail of bombs that hit Germany during World War II.
Experts estimate that close to a quarter of a million bombs dropped on Germany by the Allied Forces during World War II did not explode due to technical faults.
The industrial Ruhr area and the Lower Rhine region around Koblenz were heavily bombed, as were the cities of Dresden, Hamburg and Hanover, so this is where most unexploded ordnance come to light.
