The Hiroshima Bell of Peace tolled at 8:15 am Friday (2345 GMT Thursday), the exact moment 65 years ago when a US B-29 bomber dropped an atomic bomb on the city, killing tens of thousands of people in seconds and hundreds of thousands in the decades since, dpa reported
The first use of nuclear weapons against human beings wreaked unprecedented havoc in Hiroshima, a western Japanese city. By the end of 1945, some 140,000 people had died because of the bomb.
This year, the names of 5,501 people who were exposed to radiation and died in the last year were added at the memorial site, bringing the total of victims listed to 269,446.
The ceremony commemorating the 65th anniversary of the bombing was held at Peace Memorial Park near ground zero. Those at the ceremony observed a minute's silence in memory of victims of the attack.
"Clearly, the urgency of nuclear weapons abolition is permeating our global conscience; the voice of the vast majority is becoming the preeminent force for change in the international community," Hiroshima Mayor Tadatoshi Akiba said.
Akiba urged the Japanese government to abandon the US nuclear umbrella and to pass into law the three non-nuclear principles against the production, possession and introduction of nuclear weapons in Japan.
But Prime Minister Naoto Kan told a news conference after the ceremony, "I believe that nuclear deterrence continues to be necessary for our nation."
Kan also said Japan maintains the three non-nuclear principles against the production, possession and introduction of nuclear weapons in the country. But he stopped short of suggesting legislation of the three principles to make it law as the Hiroshima mayor demanded.
During the ceremony, United Nations Secretary General Ban Ki-moon, the first UN chief to participate in the annual event, said, "Together, we are on a journey from ground zero to Global Zero - a world free of weapons of mass destruction."
"That is the only sane path to a safer world. For as long as nuclear weapons exist, we will live under a nuclear shadow."
Ban said his own experience during the 1950-53 Korean War led him to seek peace.
"One of my earliest memories is marching along a muddy road into the mountains, my village burning behind me. All those lives lost, families destroyed, so much sadness," he recalled. "Ever since, I have devoted my life to peace. It has brought me here today."
Representatives from more than 70 countries, including US Ambassador to Japan John Roos, attended the ceremony. Roos was the first US envoy to do so. Delegations from Britain and France, both nuclear powers, also joined in for the first time.
"For the sake of future generations, we must continue to work together to realize a world without nuclear weapons," Roos said in a statement. "On the 65th anniversary of the end of the Second World War, it is fitting that we renew our determination to ensure that such a conflict is never again repeated."
The US attendance came "too late," said Haruko Moritaki, representing the Hiroshima Alliance for Nuclear Weapons Abolition. "The US is the only country on Earth that carried out atomic bombing. And they still possess nuclear arms," she said.
Japanese media coverage of the anniversary of the atomic bombing portrayed Japanese people as "victims" of World War II and rarely touched on Japan's wartime aggression.
The coverage "has become worse year by year," Kenichi Asano, a journalism professor at Doshisha University in Kyoto. That reflects Japanese journalists' "lack of correct historical perception."