Nagasaki commemorated the 55th anniversary of the U.S. atomic bombing of the city Wednesday with a call for nuclear powers to immediately begin multilateral talks so a treaty banning nuclear weapons can be concluded as early as possible.

Nagasaki Mayor Itcho Ito made the plea in a ceremony attended by about 28,000 people at Nagasaki Peace Park, near the point where the bomb exploded Aug. 9, 1945, killing an estimated 73,800 people.

Ito recounted the horrors of the bombing, saying, "Heat rays with an intensity on the ground of several thousand degrees instantly burned people's bodies, charring them black (while) invisible radiation invaded and destroyed people's cells and tissues, swiftly resulting in yet more death." Nagasaki is 300 km southwest of Hiroshima, the first city to experience to an atomic bomb attack. An estimated 140,000 people died as a result of the Hiroshima bombing, which took place three days before the devastation of Nagasaki in the closing stages of World War II.

"Nagasaki has remained the last battlefield where nuclear weapons have been used, with the unspeakably tragic experiences having served as preventative forces," Ito said in his declaration of peace.