Historian Su Zhiliang was surprised to find, after 13 years' study, that Shanghai had 149 "comfort women houses", a Japanese periphrase for brothels where Asian women were obliged to serve as sex slaves of Japanese intruding soldiers.

The professor with the Shanghai Normal University said he had not expected, when he began his research on "comfort women" in 1993, that there were so many "comfort women houses" in Shanghai.

"At that time, I thought there were at most two, but the number became larger as my research went deep," Su said.

He said that "comfort women houses" scattered throughout Shanghai metropolitan, and his discovery of the 149 houses was supported by history documents and witnesses, including Japanese archives, Japanese veterans and Chinese victims.

"The number might still rise," the researcher said.

He said he received new tips from elderly people after his book on "comfort women houses" was published recently.

About 200,000 Chinese women were forced to be "comfort women" when the nation fell victim to Japanese intrusion in the 1930s and 40s, Su said.

"I hope my research can tell those who turn a blind eye to history that the existence of 'comfort women' is an undeniable fact," Su said.

Shanghai was where Japanese army set up their first "comfort women houses", Su's research showed.

Shanghai became the largest overseas base of the Japanese navy in late Qing Dynasty (1644-1911), and in November 1931, Japan set up its first "comfort women houses" for its naval soldiers in Hongkou, a downtown area of Shanghai where Japanese people ran entertaining businesses.

Su said that was when the name of "comfort women houses" first appeared, and the city began to see more such houses in 1932, when Japanese army expanded its presence in Shanghai.

It was Okamura Yasuji, a Japanese army leader in Shanghai, that concocted the periphrase "comfort woman", the historian found.

Su said the number of "comfort women houses" in Shanghai began to rise sharply in 1937, when Japan seized the city.

The Japanese army stationed in Shanghai also issued regulations on the management of "comfort women houses", he said.

(Xinhua News Agency June 17, 2005)