Japanese Prime Minister Naoto Kan on Saturday attended the 66th anniversary in Hiroshima of the world's first atomic bomb attack, and reaffirmed the need to reduce the country's reliance on nuclear energy.

In his speech during the service to commemorate the 1945 bombing, Mr. Kan said Japan would examine the causes of this year's nuclear accident at the Fukushima nuclear power plant and aim for a society that would not depend on nuclear power generation.

Hiroshima mayor Kazumi Matsui also called for the government to review its nuclear policies, saying the continuing radiation scare has made many people live in fear and undermined people's confidence in nuclear power.

Representatives from more than 60 countries, including the United States, attended Saturday's memorial service.

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 killed an estimated 70,000 residents. Japan surrendered six days later.