WWII bomb in Berlin

The 100-kilogram bomb was discovered by construction workers just 10 centimeters below the sandy surface of a museum forecourt.

A spokesman for Berlin police said a 300-metre radius including Chancellor Angela Merkel's flat was evacuated as part of a precautionary measure around the museum which is part of Berlin's Museum Island complex of buildings that was heavily damaged during WWII.

While bomb experts worked on the device, a rail line carrying express and suburban trains was closed and streets were blocked, causing major traffic jams, police said.

Unexploded bombs from World War II are frequently found in German cities, often during digging for construction projects.

An estimated 10 to 20 percent of the Allied bombs that were dropped on German targets during World War Two failed to detonate. Many were found and destroyed immediately after the war but thousands were only discovered decades later.