In his speech at the ceremony, Prime Minister Taro Aso reaffirmed Japan's three principles of not producing, possessing or allowing nuclear weapons on its soil.
On Aug 9, 1945, a second atomic bomb was dropped by the US on Nagasaki three days after Hiroshima suffered the world's first atomic bombing. The attack, which occurred at 11:02 a.m., killed an estimated 74,000 people by the end of 1945, and many more later from radiation sickness.
Statistics showed that to date the atomic bombing has claimed a total of 149,226 lives in Nagasaki, including 3,304 people who died from injuries related to the bombing in the past year.