Foreign Minister Wang Yi reminds international community of scars left by Nanjing Massacre

US President Barack Obama paid moving tribute on Friday to victims of the world's first nuclear attack, during a historic visit to Hiroshima, but did not apologize for his country's use of the atomic bomb.

In a soaring speech watched by survivors of the atomic blast, Obama said the bomb that rent the city on August 6, 1945 "demonstrated that mankind possessed the means to destroy itself".