Almost eight decades since Yan Guiru was gripped by terror as shells rained on her Beijing neighbourhood in the opening salvos of war between China and Japan, she recalls with horror a conflict Communist leaders still use to legitimise their rule.

It was the night of July 7, 1937 when a barrage of unrelenting gun and cannon-fire erupted.

Then a recently married 17-year-old, Yan lived about 100 metres (328 feet) from the Marco Polo bridge, an ancient 11-span arch in Beijing's western suburbs mentioned in the Venetian traveller's stories.

"The guns started suddenly. Somebody shouted 'The Japanese are coming!', and then we rushed into the house, shut the door and hid under the beds," said Yan, now 95.

"I was so scared. Everyone was. I don't know how long the shelling lasted," she added.

The skirmish -- whose exact cause remains murky -- served as pretext for Tokyo's forces to seize Beijing, triggering eight years of full-scale war, which China says saw more than 20 million of its citizens die.

China's Communist leaders use historical victimhood as a key element of their claim to a right to power, and all seven members of the ruling party's politburo standing committee, its most powerful body, visited an exhibition highlighting the war at a museum near the bridge Tuesday.

"The great contributions made by the Chinese people to the world anti-Fascist war should be remembered," President Xi Jinping said at the "Great Victory, Historic Contribution" exhibition, according to a report by state news agency Xinhua.

Chinese Premier Li Keqiang also visited the exhibition in the afternoon, Xinhua said, while earlier, in front of giant red banners, another politburo standing committee member, Liu Yunshan, addressed hundreds of military personnel, veterans and schoolchildren.

Beijing regularly accuses Tokyo of failing to fully acknowledge wartime atrocities, and relations between the Asian powers have plunged in recent years as it aggressively asserts its claims to disputed islands in the East China Sea.

When the gunfire stopped Yan's petrified family -- she lived with her husband, his parents and sisters -- emerged from under their beds but were too scared to go outside for days.

Japanese troops -- who had been allowed in China under terms set after foreign forces put down the 1900 Boxer Rebellion -- appeared to be patrolling the area as occupiers, she said.

Eventually soldiers broke down the door, and Yan and her sisters-in-law hid behind their husbands, fearing they could be dragged away and raped.

"Thankfully, they did not take us," Yan said. "But they stole our pig, a chicken and everything they could find to eat."

- 'History of humiliation' -

Tuesday's ceremony at the Museum of the Chinese People's War of Resistance against Japanese Aggression fits into months of commemorations for the 70th anniversary of the conflict with Japan and the World Anti-Fascist War, as Beijing calls the global conflict.

They will culminate in September with a huge military parade in Beijing.

Xinhua said Monday that in the run-up to the march the country's "silver screens and theatre stages will be dominated by a wave of war stories about Japan's invasion of China".

No fewer than 183 stage performances will be mounted, it said, with 10 new films, 12 TV series, 20 documentaries and three cartoon series aired nationwide, and more than 100 books and 20 electronic publications released.

The drive was intended to "illustrate the Chinese people's bitter journey towards victory" and "highlight the anchoring role" the Communist Party played in the war, it quoted Tian Jin, the deputy head of China's media regulator, as saying.

For decades, the ruling party has played down the role of the larger Nationalist forces -- which they defeated at the end of China's civil war in 1949 -- in the conflict with Japan.

Instead the Communist Party stresses that under its leadership, China finally overcame more than a century of humiliation by outside powers dating back to the Opium Wars of the 19th century.

It uses the "history of humiliation" to achieve "unity and popular connection with the public", said Kerry Brown, professor of Chinese politics at the University of Sydney.

It was particularly important for President Xi, Brown said, with his "Chinese Dream" concept based around "the country being poised to retake its great power status and be respected and admired globally".

"History as a political tool rather than an academic discourse is something that he cannot, and as a politician will not, ignore," he said. "So we have to expect more of this."

- 'Down with the little Japanese' -

It is a deep-seated narrative among ordinary Chinese.

Yan still occupies the same traditional one-storey courtyard house where she lived in 1937 and neighbours greet her respectfully as she edges forward with tiny steps on minute feet.

"Tell them 'Down with the little Japanese!'" one of her neighbours shouted as she talked to AFP.

The slogan was chanted by many taking part in anti-Japanese protests that Chinese authorities allowed to take place in 2012 after Tokyo formally nationalised tiny islets known as the Diaoyus in China and the Senkakus in Japan.

"I don't think Japan has admitted its crimes even today," Yan said. "And I don't think Japan will ever be a good friend of China."