The world is marking the 81st anniversary of the Hiroshima and Nagasaki nuclear bombings carried out in the final days of World War II. The US attacks, carried out respectively on August 6 and 9, 1945, killed an estimated 150,000 to 246,000 people, including the immediate victims of the fission blasts and those who succumbed to wounds and radiation sickness by the end of the year.