Girls in the Tiger Cage 2 (1976)

Original title: Yeosu 407ho 2 aka: Prisoner 407 (part 2) / Revenge in the Tiger Cage / Operation First Team Japan conquers China just before WW2 starts. Chinese women are captured and placed in concentration camps, where they are tortured and humiliated. Some try to escape incurring enormous risks, and death if they fail.