FILE PHOTO: Aerial photo shows the main railway station Hauptbahnhof in Berlin, Germany, May 29, 2016. REUTERS/Hannibal Hanschke/File Photo

BERLIN (Reuters) - Berlin’s central train station, the Economy Ministry, a museum and part of the Charite hospital will be evacuated on Friday while a World War Two bomb is defused, police said on Wednesday.

The 500-kilogram British bomb was found during building work in central Berlin, and all buildings within an 800 metre radius will be evacuated from 9 am local time (0700 GMT), police said on Twitter.

The evacuation area includes the Natural History Museum.

Police spokesman Martin Halweg said it was not yet clear how long the evacuation would last or whether Tegel airport would be affected.

“We have a defusal on this scale around once or twice a year in Berlin,” he said.

Of the bomb itself, police said on Twitter: “It is safe - there is no immediate danger.”

More than seven decades after the end of World War Two, Germany still discovers more than 2,000 tonnes of live bombs and munitions every year.

Last year some 60,000 people were evacuated from their homes in Frankfurt after a massive bomb dropped by Britain’s Royal Air Force was unearthed.