"This was the largest post-war evacuation in Hanover," said fire brigade spokesman Alfred Falkenberg.
"I hope the evacuations will end one day, but there are probably several hundred bombs still buried."
The bombs were found buried between three and six metres below the surface in a north Hanover quarter after local authorities studied aerial photos made available by Britain and the United States.
One of the bombs -- believed to have been dropped in a British attack in October 1943 -- was buried in a garden just a few metres from a house while, the other two were detected and then removed from under open fields.
Hanover, with a population of 520,000 people, is a northern industrial centre and transport hub that was heavily bombed during the war.
Mr Falkenberg said more than 10,000 bombs were dropped on Hanover in the war and 15 per cent failed to explode.
"We'll find them all sooner or later," he said.