Hiroshima (AsiaNews/Agencies) - Ceremonies have been taking place in the Japanese city of Hiroshima exactly 60 years after the world's first atom bomb was dropped there.

Thousands gathered at the city's Peace Park, including survivors of the bombing and relatives of some of the 140,000 people killed.

During the ceremony another 5,375 names were added to the list of Hiroshima's dead.

In his address, the city's mayor Tadatoshi Akiba accused the five established nuclear powers - the United States, Russia, Britain, France and China - and India, Pakistan and North Korea of jeopardising human survival.

Japan's Prime Minister was more subdued, reiterating his country's opposition to nuclear weapons while offering prayers for the dead.

At 8:15am, the time when the US B-29 warplane Enola Gay dropped the bomb, people at the park and throughout the city observed a minute's silence in memory of those who perished.

Bells at temples and churches rang and passengers on the streetcars that run throughout the city bowed their heads in remembrance of the dead.

"This August 6 ... is a time of inheritance, of awakening, and of commitment, in which we inherit the commitment of the bomb victims to the abolition of nuclear weapons and realisation of genuine world peace," Mr Akiba told the gathering.

On August 9, 1945, three days after the Hiroshima attack, another atomic bomb was dropped on Nagasaki. Japan surrendered on August 15, ending the military aggression that brought it into World War Two.

Yohei Kono, the speaker of parliament's lower house, said the Hiroshima anniversary should remind Japan not to return to militarism and the world not to use nuclear weapons again.

"We made a mistake in choosing our path in Asia and followed a road to war," Kono said.