Hiroshima on Sunday commemorated the 55th anniversary of its 1945 atomic bombing in a ceremony attended by the Russian ambassador to Japan, the first envoy from a full-fledged nuclear power to join the annual event.

Young women place floating lanterns in the river at Peace Memorial Park to pray for the A-bomb victims.

After a one-minute silent prayer held under the scorching sun at 8:15 a.m., when the atomic bomb was dropped on the city 55 years ago, Mayor Tadatoshi Akiba delivered an annual peace declaration.

"Having called on the world to abolish nuclear weapons, Hiroshima wishes to make a new start as a model city demonstrating the use of science and technology for human purposes," Akiba said in the city's Peace Memorial Park near ground zero.

"We will create a 21st century in which Hiroshima's very existence formulates the substance of peace," he said at the final memorial ceremony this century.