The movie is a realistic viewing of the 1937 "Rape of Nanjing" committed to the Chinese civilians by the Japanese Imperial Army.
Nanjing is bombed multiple times. The film shows the killings of many people. Many are shot. Some are stabbed. Some are beaten to death.
A few children are killed throughout the course of the movie.
The entire last 15 minutes of the movie shows the massacre of the refugee camp. Countless women are taken and get their clothes ripped off. Then they are held down and raped. It even shows some children being raped (although no nudity between them is shown). It is really hard and disturbing to watch.
The movie in it's entirety is very disturbing and emotional.