About 12,000 people were forced to leave their homes, offices, schools and businesses in the eastern German town of Oranienburg on Wednesday as officials work to defuse a World War II bomb.

A 900-meter area was cleared around the site where the unexploded 250-kilogram United States aircraft bomb was discovered during a systematic search last November of the town, which is less than 40 kilometers north of the German capital, Berlin.

Residential buildings, day nurseries, schools as well as the local district administration buildings were evacuated as a six-member denotation team began the hours-long task of defusing the bomb.

Rail traffic and shipping on the network of canals that run through the town, which has a population of about 45,000, have also been interrupted by the action.