The Hiroshima bomb is the most devastating to have been used in real combat. But today’s nuclear weapons are far, far more powerful

Japan marks 80 years since the atomic bombing of Hiroshima today with a ceremony reminding the world of the horrors unleashed, as sabre-rattling between the United States and Russia keeps the nuclear “Doomsday Clock” close to midnight.

Hiroshima Day is observed annually on August 6 to commemorate the victims of the world's first nuclear attack.