BERLIN: Around 20,000 people were being evacuated from central Cologne Wednesday after three unexploded World War II bombs were found, the biggest such operation in the German city since the end of the war.

Bomb squad technicians were planning to defuse the three American explosives, two weighing 1,000 kilograms (2,204 pounds) and one 500 kg, which were found during building work Monday in the Deutz area on the east bank of the River Rhine.

Road and train lines were closed and city officials were going door to door to clear the evacuation zone of about 10,000 square metres which included three bridges over the Rhine.

The heart of the city was left deserted, with a hospital, two old people’s homes, nine schools, a TV studio and dozens of hotels affected.

Building works in Germany have regularly unearthed unexploded World War II ordnance.

In Frankfurt, the discovery of a 1.4-tonne bomb in 2017 led to the removal of 65,000 people, the biggest such evacuation in Europe since 1945.

In 2021 four people were injured when a World War II bomb exploded at a building site near Munich’s main railway station, scattering debris over hundreds of metres.