Around 20,000 people being evacuated after unexploded Second World War bombs discovered in Cologne

Around 20,000 people are being evacuated from their homes in the German city of Cologne as experts try to defuse three Second World War bombs.

It's the biggest ever post-war evacuation in the city and follows the discovery of two 1,000kg and one 500kg American devices on Monday. The size of the bombs means that a 1,000m danger zone has to be cordoned off and closed.

Officials have been going door to door checking that businesses and houses in Cologne's Old Town and Deutz areas are empty. Nine schools, 58 hotels, a hospital, the main city hall and the area close to Cologne's famous UNESCO-listed cathedral are among the numerous places temporarily off limits.

Two shelters have been set up for those affected. It's reported that 1.5 million bombs were dropped on Cologne during the Second World War.

Experts estimate around 20% didn't fully detonate. Some of these so-called "duds" still lie unexploded beneath the streets and have prompted numerous evacuations over the years.

Read more:Little ships recreate historic Dunkirk rescue In 2024, 31 bombs were found in the city, requiring 17 evacuations, impacting more than 36,000 people. Among the duds discovered were a 1,000kg American bomb and five 500kg bombs, as well as several grenades.

City officials have told Sky News that the plan is to try to defuse the bombs. If that isn't possible, then another option would potentially be to detonate them safely.

This would be a much larger operation and require sand and water to be brought to the area to help limit the blast damage. Authorities hope that if all goes to plan, bomb disposal experts will be able to defuse them in time to allow people to return to their houses by Wednesday night.

Cologne was the first German city to experience a '1,000 bomber raid' by the Royal Air Force during World War Two. Some 1,400 tons of bombs were dropped in a single night on 30 May, 1942.

It's unclear which raids the bombs being defused today are from..