The Chinese government launched a full-scale propaganda attack today on a conference in Japan organized to deny that the 1937 Nanking Massacre of Chinese civilians by Japanese troops took place.

The Foreign Ministry, the Communist Party's People's Daily and the official New China News Agency all released lengthy attacks on the conference, staged by a group of Japanese rightists at the International Peace Center of Osaka. Conference organizers have called reports of the massacre, popularly called the Rape of Nanking, "the biggest myth of the 20th century."

Foreign Ministry spokesman Zhu Bangzao accused Japan and authorities in Osaka, Japan's second-biggest city, of taking a "laissez-faire" attitude toward the massacre and of "seriously hurting the feelings of the Chinese people and disturbing the growth of Sino-Japanese relations." The New China News Agency warned that Sino-Japanese relations would be undermined if forces in Japan continue to deny atrocities committed by Japanese forces in China during the 1930s and '40s.

The Chinese government's reaction to the conference was unusual in its intensity, and it illustrated the enduring tension between Tokyo and Beijing over Japanese excesses in Nanking--now called Nanjing--and other areas of China during and prior to World War II. Japanese soldiers killed millions of Chinese during their eight-year occupation, a period remembered very clearly in China but given scant attention in Japan.

One of the bloodiest incidents occurred in Nanking when marauding Japanese soldiers butchered tens of thousands of Chinese, raped thousands of women and burned down much of the city, then China's capital. The story was the subject of a recent best-selling book by Chinese American journalist Iris Chang, "The Rape of Nanking."

Japan has never owned up to such atrocities, and the Nanking Massacre is rarely mentioned in Japanese textbooks or histories. Chinese President Jiang Zemin failed to secure a clear apology from the Japanese government for its wartime behavior in a 1998 visit to Japan that Beijing viewed as a diplomatic disaster.

As such, China is particularly sensitive to signs that Japan is growing more tolerant of historical revisionists seeking to rewrite or expunge Japan's record of wartime misdeeds.