China is marking the 75th anniversary of the Nanjing Massacre.
Beijing says 300,000 civilians and soldiers were killed in the first six weeks of the Japanese occupation which started in 1937.
On its website, the Japanese foreign ministry concedes only that "the killing of a large number of noncombatants ... occurred" and says that "it is difficult to determine which the correct number is".
The issue remains one of the biggest factors that divide the two nations to this day.
Al Jazeera's Stephanie Scawen reports.