Thursday marks the 64th anniversary of the atomic bomb attack on Japan's Hiroshima.

The US attack devastated the city and killed hundreds of thousands of people during World War Two.

Hiroshima held an annual memorial ceremony on Thursday. Japanese Prime Minister Taro Aso addressed the solemn crowd gathered for the mourning.

He called for international support for Japan's ongoing efforts to halt nuclear proliferation.

The Hiroshima Mayor Tadatoshi Akiba also delivered a peace declaration, calling for the abolition of nuclear weapons by 2020.

An estimated 140-thousand people were killed instantly or died within a few months of the bombing on August the 6th, 1945. Three days later, another atomic bomb was dropped on Nagasaki, also in Japan.