An unexploded World War II bomb has been unearthed near Berlin's main train station, risking possible disruptions to rail and road traffic, authorities said Wednesday

"The bomb was found yesterday afternoon on property belonging to the rail company," a police spokesman told AFP, adding that the 100-kilogramme (220-pound) explosive was dropped by the Allies during the Second World War.

The site lies about 1.5 kilometres (0.9 miles) north of the main train station and the spokesman said police were still determining how to re-route road traffic around the area.

A spokesman for the rail operator, Deutsche Bahn, said it was deliberating whether to re-direct trains while authorities defuse the bomb or destroy it in a controlled explosion.

More than six decades after the war, authorities believe there are still some 3,000 bombs buried beneath Berlin alone, and unexploded devices are regularly discovered in construction work.

In June 2010, a 500-kilo Allied bomb, thought to be British, exploded and killed three German sappers, and seriously injured two others in the central city of Goettingen as they prepared to defuse it.

[Image via Agence France-Presse]