The Japanese city of Nagasaki on Sunday commemorated the 75th anniversary of its destruction by a US atomic bomb, with its mayor and the head of the United Nations warning against a nuclear arms race. Nagasaki was flattened in an atomic inferno three days after Hiroshima — twin nuclear attacks that rang in the nuclear age and gave Japan the bleak distinction of being the only country to be struck by atomic weapons. Survivors, their relatives and a handful of foreign dignitaries attended a remembrance ceremony in Nagasaki where they called for world peace. Participants offered a silent prayer at 11:02 am (0202 GMT), the time the second and last nuclear weapon used in wartime was dropped over the city. “The true horror of nuclear weapons has not yet been adequately conveyed to the world at large” despite decades of effort by survivors telling of their “hellish experience”, Nagasaki mayor Tomihisa Taue said in a speech afterwards. “If, as with the novel coronavirus — which we did not fear until it began to spread among our immediate surroundings — humanity does not become aware of the threat of nuclear weapons until they are used again, we will find ourselves in an irrevocable predicament.”UN Secretary General Antonio Guterres, in a message read by his undersecretary Izumi Nakamitsu, warned that “the prospect of nuclear weapons being used intentionally, by accident or miscalculation, is dangerously high.” “The historic progress in nuclear disarmament is in jeopardy… This alarming trend must be reversed,” he said.‘Nuclear-free world’ The number of participants in this year’s ceremony was reduced to roughly one tenth the figure in previous years due to coronavirus fears, with proceedings broadcast live online in Japanese and English.Prime Minister Shinzo Abe refreshed his pledge that Japan would lead “the international community’s efforts towards the realisation of a nuclear-free world”. Terumi Tanaka, 88, who was 13 and at his hillside home when the bomb hit Nagasaki, remembers the moment everything went white with a flash of light, and the aftermath.