By the eve of the Pacific War, the Chinese population in New Guinea exceeded 2,000.
After the Japanese attack on Pearl Harbor, with the Japanese invasion of New Guinea looming just over the horizon, the Australian government moved to evacuate white women and children from the territory. However, they made no similar moves to evacuate the Chinese population there. In early 1942, in response to the pleas of community members, this stance softened slightly, and 300 Chinese were flown to Australia; however, the majority of Chinese women were refused permission to leave. Left behind to face occupation by the Imperial Japanese Army, Chinese women became victims of atrocities at a far higher rate than indigenous women. According to community leader Chin Hoi Meen, "Chinese girls had to be supplied to [the Japanese] on demand"; under threat of beatings, death, or imprisonment in a soldiers' brothel as comfort women, Chinese women were also forced to enter into relationships and cohabit with Japanese officers. Chinese men were interned in concentration camps to perform hard labour. A total of 86 local Chinese residents died during the war, 37 of those having been killed by the Japanese. Among the dead was the head of the PNG branch of the Kuomintang, the main political party of the Republic of China at the time; he was executed by Japanese troops as a warning to the community.
In addition to their crimes against local Chinese people, the Japanese sent about 1,600 Republic of China Army prisoners-of-war to Rabaul as slave labourers; many died and were buried there. Some soldiers of Taiwan origin came as auxiliaries with the Japanese army as well.