NANJING, China (Reuters) - China pressed a propaganda campaign against Japan this week with a guided visit to the site of the 1937 Nanjing massacre, holding up proof to refute doubts by some in Japan about the extent of the atrocity or even that it happened at all.
China's ties with Japan have long been poisoned by what China sees as Japan's failure to atone for its occupation of parts of China before and during World War Two.
China is determined to sustain the memories.
Japanese leaders have made repeated apologies for the suffering that Japan's Imperial Army inflicted but remarks by conservative politicians have cast doubt on Japan's sincerity.
Japanese troops battling Chinese forces captured Nanjing in late 1937. The city, then known as Nanking, was the Chinese capital.
China says in the weeks that followed, Japanese troops killed 300,000 people. A post-war Allied tribunal put the death toll at 142,000.
To the fury of China, some conservative Japanese politicians and academics deny that the massacre took place, or they put the death toll much lower.
Just this month, China criticised a member of the board of Japan's state broadcaster for saying the massacre did not happen.
China's anger over the past is never far from the surface of relations that have deteriorated sharply over the past 18 months because of a dispute over a chain of islands in the East China Sea.
Ships from both countries shadow each other around the islets and Japan has scrambled jets numerous times in response to Chinese aircraft, raising fears of a clash.
Ties have worsened since China demarcated an air defence identification zone over the East China Sea and a visit in December by Japanese Prime Minister Shinzo Abe to Tokyo's Yasukuni Shrine honouring war criminals among war dead.
Compounding China's suspicion is the belief that Abe is intent on revising Japan's pacifist constitution adopted after its World War Two defeat.
On a two-day trip to Nanjing which ended on Thursday, Chinese officials reminded foreign reporters of Japan's aggression, showing them skeletons of victims in a memorial hall and letting them hear the testimony of an octogenarian survivor, Xia Shuqin.
Xia, 83, tearfully recounted how Japanese troops on December 13, 1937, killed her whole family except her and her four-year-old sister.
"There are still Japanese who are so bad," she said. "Some still deny history and call me a fraud. I escaped from the massacre and crawled out from under dead bodies."
"The evidence is not fabricated by the Chinese, there are too many documents including many foreign government documents," said Zhang Xianwen, a Nanjing University historian who worked on a compendium of documents of the massacre.
At the municipal archives, researchers wearing white gloves displayed about a dozen time-worn documents relating to the massacre, pulling them one-by-one from a beige lock-box and holding them up for the group to see.
The documents appeared brittle and tanned with age. Some were hand-written, with red marks from chop used to stamp people's names.
"We are doing this with the purpose of letting the archives talk ... The massacre can never be denied," said Wang Han, deputy director general of the Nanjing Archives Bureau.
"Facts are always facts. I can't help it if some people do not admit to them. Archives are proof of the facts, recordings of the truth are the most forceful form of proof. You could say that the proof of the archives speaks louder than the denials."
As Chinese officials were keeping the history alive in Nanjing, Abe was telling parliament in Tokyo that Japan had caused great pain and his government would stand by past apologies.
"As I've said before, in the past many nations, especially those in Asia, suffered great damage and pain due to our nation. Our government recognises this, as have the governments that have gone before, and will continue this stance," he said.
Additional reporting by Linda Sieg in TOKYO; Writing by Ben Blanchard; Editing by Robert Birsel