Nanjing Requiem, By Ha JinThe Flowers of War, By Geling Yan, trans. Nicky Harman

Ha Jin's novel Nanjing Requiem begins with the words of a Chinese servant boy, Ban, forced to witness an orgy of pillage and murder as the victorious Japanese army rampage through China's fallen former capital. Ban's shell-shocked voice serves as a memorable opening chapter. The Japanese have killed so many people that the bodies pollute the streams and wells. Rice cooked with the water turns red.

In December 1937, Japanese troops seized Nanjing from Chiang Kai-shek's Nationalist forces. In the "Rape of Nanking", the conquering army inflicted six weeks of barbaric cruelty on the city, murdering over 250,000 people and raping and torturing 20,000 women, according to Chinese estimates. This savagery has been subject of countless films, novels and histories and remains controversial. Some factions in Japan deny the massacre happened, while China views it as perhaps the single most tragic episode of its modern history.

These two new works of fiction provide further accounts of the period. Both novels are inspired largely by one true event. During the massacre Minnie Vautrin, an American missionary, saved thousands of lives by sheltering up to 10,000 women and children in her Ginling College campus. Vautrin's diaries record an incident in which Japanese soldiers demanded the use of 100 prostitutes hiding in the refuge. With little choice, Vautrin allows them to take their pick, knowing that gang rapes and possibly brutal death awaited these "comfort women" in army brothels.

This episode forms the backdrop of Minnie's fatal breakdown in the US-based Ha Jin's Nanjing Requiem, which tells the story of her heroism through the eyes of her sensible and stoic (fictional) Chinese assistant, Anling Gao. Minnie is consumed by guilt that she did not help those dragged away. Her obsessive bid to save one young girl - who ends up deranged in a mental hospital, where she is abused as a sex slave - mirrors her own mental decline, which culminated in her suicide in 1941.

In The Flowers of War by Chinese bestseller Geling Yan, Vautrin appears briefly at the end. Instead, the book tells the story of a fictional group of schoolgirls sheltering in a church under the protection of a pair of good-hearted Western priests. As Nanjing burns, 13 prostitutes from the Qin Huai River brothels clamber over the wall and beg for clemency. When the Japanese arrive asking for "girls", Father Englemann - like Vautrin - must make a life-and-death choice. The novel (beautifully translated by Nicky Harman) appears in English to coincide with its adaptation by China's best-known director, Zhang Yimou. Despite his budget of over $90 million (the most expensive film ever in Chinese cinema), critics have accused him of selling out with Hollywood-style sexing-up of a traumatic period.

Thankfully, Yan's novel is more nuanced. Shujuan, one of the schoolgirls, forms the moral arc of the story. Trapped in the church, she is furious at the changes in her body, at the war raging outside and, above all, at the prostitutes whom she views with disgust. Yan masterfully depicts these bubbling tensions. In a savage scene, the schoolgirls beat up a pretty teenage prostitute, pulling out hanks of her hair and scratching her face. While characters such as the beautiful and soulful brothel leader Zhao Yumo verge on the "hooker with a heart" cliché, such moments provide the novel with a painful authenticity.

By contrast, Nanjing Requiem is a strangely anaemic book. We see the horrors inflicted on the city through the eyes of middle-aged Anling: a woman with a pragmatic obsession for details that elicit few emotions. The use of the first-person, above all, renders other characters one-dimensional and distant.

Minnie appears more like a paper saint than a woman afflicted by the crippling doubt that killed her. Ha Jin writes in his second-language English, and his sparse prose can achieve a masterful precision. Yet stilted conversation often dulls the drama. However, both novels demonstrate how humans cope when forced together in wartime, and they map the bitter rivalries and tentative camaraderie, that ensue. Sitting at the centre are stories of sacrifice. Both are testament to the bravery of women in the most horrifying of circumstances.