ブリタニカでは南京事件について、以下のように表示されています。
犠牲者数についての論争があることを示しつつ、ほとんどは10万人から30万人以上と評価されている
ことを記載しています。

Nanjing Massacre, conventional Nanking Massacre, also called Rape of Nanjing, (December 1937-
January 1938), mass killing and ravaging of Chinese citizens and capitulated soldiers by soldiers
of the Japanese Imperial Army after its seizure of Nanjing, China, on Dec. 13, 1937, during the Sino
-Japanese War that preceded World War II. The number of Chinese killed in the massacre has been
subject to much debate, with most estimates ranging from 100,000 to more than 300,000.
http://www.britannica.com/EBchecked/topic/402618/Nanjing-Massacre
`

２０１２年２月２３日付米国メディアＣＮＮから。
出だしが「日本の市長が、多くの記録によって立証された、７０年以上前に中国で起きた虐殺事件を
軽く見て怒りを呼んでいる」。
次の段が「南京に侵入した日本軍のレイプ、殺人、略奪で殺された市民は３０万人と見積もられる」。
次が「事件は最近クリスチャン・ベール主演の映画『ザ・フラワーズ・オブ・ウォー（戦争の花）』で描かれた」。

・参考：CNN報道
Fury over Japanese politician's Nanjing Massacre denial By Paul Armstrong, CNN
February 23, 2012 -- Updated 1418 GMT (2218 HKT)
Hong Kong (CNN) -- The mayor of a Japanese city has sparked outrage after playing down a well-documented
massacre of civilians in China's former capital more than 70 years ago.
An estimated 300,000 people died when Japanese troops invaded the city of Nanjing in China's Jiangsu
province in 1937, unleashing a campaign of rape, murder and looting that became known as the Nanjing
Massacre.
The event was recently portrayed in a movie starring Christian Bale called "The Flowers of War."
(略)
http://edition.cnn.com/2012/02/23/world/asia/china-nanjing-row/index.html