Seventy years ago, on 6 August 1945, the US dropped an atomic bomb on the Japanese city of Hiroshima, followed three days later by an attack on Nagasaki. The first and only time nuclear weapons have been used in warfare, the atomic blasts devastated the two cities and killed at least 129,000 people.

The attack came during the closing days of the Second World War, when after victory in Europe had been achieved a fierce battle between the Allies and the Empire of Japan was taking place in the Pacific.

After US president Harry S Truman gave the order, it was a US B-29 Superfortress Enola Gay, carrying 12 crew members, that dropped the atomic bomb, nicknamed "Little Boy", on Hiroshima. Three days after the Hiroshima bombing, the US dropped an atomic bomb nicknamed "Fat Man" on Nagasaki. Japan surrendered six days later on August 15 1945, bringing the Second World War to an end.

The archive video of these historic events compiled here shows the American crew posing in front of the Enola Gay before departure, colour footage of the Nagasaki explosion, the aftermath of the atomic bomb on the devastated city of Hiroshima and blast victims being treated afterwards.