structural:expansion, structural:summarization
Extrajudicial killing of Chinese prisoners of war and male civilians

Soon after the fall of the city, Japanese troops made a thorough search for Chinese soldiers and summarily arrested thousands of young Chinese men. Many were taken to the Yangtze River, where they were machine-gunned to death. What was probably the single largest massacre of Chinese troops, the Straw String Gorge Massacre, occurred along the banks of the Yangtze River on December 18. For most of the morning, Japanese soldiers tied the POWs' hands together. At dusk, the soldiers divided POWs into four columns and opened fire. Unable to escape, the POWs could only scream and thrash desperately. It took an hour for the sounds of death to stop and even longer for the Japanese to bayonet each individual. The majority of the bodies were dumped directly into the Yangtze River.

Japanese troops gathered 1,300 Chinese soldiers and civilians at Taiping Gate and murdered them. The victims were blown up with landmines, then doused with petrol and set on fire. The survivors were killed with bayonets.

A soldier from the IJA's 13th division described killing survivors in his diary:

"I figured that I'd never get another chance like this, so I stabbed thirty of the damned Chinks. Climbing atop the mountain of corpses, I felt like a real devil-slayer, stabbing again and again, with all my might. 'Ugh, ugh,' the Chinks groaned. There were old folks as well as kids, but we killed them lock, stock, and barrel. I also borrowed a buddy's sword and tried to decapitate some. I've never experienced anything so unusual."

U.S. news correspondents F. Tillman Durdin and Archibald Steele reported seeing corpses of massacred Chinese soldiers forming mounds six feet high at the Nanjing Yijiang gate in the north. Durdin, who worked for The New York Times, toured Nanjing before his departure from the city. He heard waves of machine-gun fire and witnessed the Japanese soldiers gun down some two hundred Chinese within ten minutes. He would later state that he had seen tank guns used on bound soldiers.

Two days later, in his report to The New York Times, Durdin stated that the alleys and streets were filled with the dead, amongst them women and children. Durdin stated "t should be said that certain Japanese units exercised restraint and that certain Japanese officers tempered power with generosity and commission," but continued "the conduct of the Japanese army as a whole in Nanjing was a blot on the reputation of their country"."

Ralph L. Phillips, a missionary, testified to the U.S. State Assembly Investigating Committee, that he was "forced to watch while the Japs disemboweled a Chinese soldier" and "roasted his heart and liver and ate them."

Just after Christmas, the Japanese set up public stages where they called upon former Chinese soldiers to confess, claiming they would not be harmed. When over 200 former soldiers did come forward, they were promptly executed. When former soldiers stopped identifying themselves, the Japanese began rounding up groups of young men who "aroused suspicion."

Based on the dutiful records of the Safety Zone committee, the post-war International Military Tribunal found that some 20,000 Chinese male civilians were killed on false accusations of being soldiers, while some 30,000 genuine former combatants were executed and their bodies thrown in the river.