BEIJING China said on Monday it was extremely unhappy with Japan for lodging a protest over comments in Germany by Chinese President Xi Jinping, who recalled Japan's wartime invasion of the city of Nanjing and resulting massacre.
Xi, in a speech in Berlin on Friday, said that such atrocities were "still fresh in our memory" and referred to the Chinese figure of 300,000 being killed.
China consistently reminds its people of the 1937 Nanjing Massacre in which China says Japanese troops brutally killed 300,000 men, women and children in the then national capital.
A post-war Allied tribunal put the death toll at 142,000, but some conservative Japanese politicians and scholars deny a massacre took place.
Japanese Chief Cabinet Secretary Yoshihide Suga said on Sunday that Japan did not deny that members of the Japanese military had been involved in killings and lootings in Nanjing but said there were various views about the number of victims.
He said it was extremely regrettable for a Chinese leader to make remarks about Japan's history in a third country and that Japan had protested.
Chinese Foreign Ministry spokesman Hong Lei said it was Japan that was in the wrong for daring to criticize Xi's remarks.
"We are extremely dissatisfied with Japan's unjustified stance and strongly protest," Hong told a daily news briefing.
Xi cited historical facts to ensure that people always remember what happened to ensure such tragedies can be avoided in the future, Hong added.
"The crimes of the Japanese militarists in invading China, including the Nanjing Massacre are historical facts that cannot be denied," he said.
"Recently, there has been a trend in Japan towards beautifying and denying the history of aggression, which has attracted high concern and caused alarm internationally amongst those who love peace."
China's ties with Japan have long been poisoned by what Beijing sees as Tokyo's failure to atone for its occupation of parts of China before and during World War Two.
During his speech, Xi also lauded German businessman John Rabe, a man lionized in China for his role in protecting Chinese from Japanese troops who rampaged through Nanjing, then known as Nanking.
China has increasingly contrasted Germany and its public contrition for the Nazi regime to Japan, where repeated official apologies for wartime suffering are sometimes undercut by contradictory comments by conservative politicians.
Deteriorating relations between Beijing and Tokyo have been fuelled by a row over a chain of disputed islands in the East China Sea. Ships from both countries frequently shadow each other around the islets, raising fears of a clash.
Ties have further worsened since China's creation of an air defense identification zone over the East China Sea and Japanese Prime Minister Shinzo Abe's visit to the controversial Yasukuni Shrine honoring war criminals among Japan's war dead.
(Reporting by Ben Blanchard; Additional reporting by Linda Sieg in TOKYO; Editing by Nick Macfie)