Hiroshima marked the 67th anniversary of the world's first atomic bomb attack Monday, amid a rising tide of anti-nuclear sentiments in Japan following the nuclear accident at a power plant in Fukushima last year.
About 50,000 people, including Prime Minister Yoshihiko Noda and a number of foreign representatives, attended the annual ceremony in Hiroshima's peace park.
The remembrance began with the ringing of a bell and a moment of silence.
Hiroshima Mayor Kazumi Matsui urged the Japanese government to establish an energy policy that is safe and secure.
The bomb that the U.S. dropped on Hiroshima killed around 140,000 people, either instantly or from radiation burns days later. Another bomb dropped on the port city of Nagasaki three days later, killing an estimated 70,000 residents. Japan surrendered six days later.