The city was a major Japanese military hub with factories, military bases and ammunition facilities in the Second World War and the uranium bomb killed around 140,000 people and hastened Japan’s surrender.
Survivors, politicians and others took part in a ceremony to remember the tragedy of August 6 1945 when the US struck the city in western Japan.
Japanese Prime Minister Shinzo Abe bowed in front of Hiroshima Memorial Cenotaph (AP Photo/Eugene Hoshiko)
Visitors observed a minute of silence for the victims of the atomic bombing, at 8.15am (AP Photo/Eugene Hoshiko)
Kazumi Matsui, right, mayor of Hiroshima, and the family of the deceased bow before they place the victims list of the Atomic Bomb at Hiroshima Memorial Cenotaph during the ceremony (AP Photo/Eugene Hoshiko)
The families of the deceased offered flowers to Hiroshima Memorial Cenotaph (AP Photo/Eugene Hoshiko)
Japanese Prime Minister Shinzo Abe was at the commemoration (AP Photo/Eugene Hoshiko)
Mr Abe bowed to the families of the victims (AP Photo/Eugene Hoshiko)
Visitors observed a minute of silence for the victims of the atomic bombing (AP Photo/Eugene Hoshiko)
The four-ton bomb was dropped from a B-29 bomber and exploded at 8.15am. (AP Photo/Eugene Hoshiko)
Workers prepared wreaths for the atomic bombing victims (AP Photo/Eugene Hoshiko)
While a visitor lit a candle in front of the cenotaph for the atomic bombing victims before the start of the ceremony (AP Photo/Eugene Hoshiko)