Meanwhile, the Japanese units on mopping-up duty in Nanking had decided that the former Chinese soldiers hiding in the city were a possible security risk and therefore carried out a thorough search of every building in Nanking and made frequent incursions into the Nanking Safety Zone in search of them. Japanese units attempted to distinguish former soldiers from civilians by checking if they had marks on their shoulders from wearing a backpack or carrying a rifle. However, the criteria used were often arbitrary as was the case with one Japanese company which apprehended all men with "shoe sores, callouses on the face, extremely good posture, and/or sharp-looking eyes" and for this reason many civilians were taken at the same time. What happened to the Chinese soldiers and civilians who were captured varied greatly from unit to unit, though many were summarily executed in an event that came to be known as the Nanking Massacre, which the foreign residents and journalists in Nanking made known internationally within days of the city's fall. The Japanese also committed random acts of murder, rape, looting, and arson during their occupation of Nanking. According to the International Military Tribunal for the Far East, indicate that the total number of civilians and prisoners of war murdered in Nanking and its vicinity during the first six weeks of the Japanese occupation was over 200,000 while 20,000 women were raped, including infants and the elderly. Estimates for the total death toll of the Nanking Massacre vary widely.