'World has to reflect on comfort women'

With only dozens of "comfort women" alive today, a prominent historian of their plight called for international efforts to preserve the historical documents for future generations.

"A lot of the documents and photos of 'comfort women' were ruined by fire or water as the Japanese military tried to destroy the evidence when they were defeated," said Su Zhiliang, a history professor at Shanghai Normal University, who has spent more than two decades researching the "comfort women" system and campaigning on behalf of the victims.

The Japanese military set up the first "comfort stations" in Shanghai in 1932. By the time of the full-scale invasion in 1937, the military brothels where women were forced into sexual slavery were all over China, from northernmost Heilongjiang to southernmost Hainan Island, said Su during a visit to San Francisco at the invitation of the Comfort Women Justice Coalition in that city.