By October, Chiang Kai-shek's best armies had been defeated at Shanghai. By the end of the year, the Chinese capital at Nanjing had also been seized. The use of brutal scorched earth tactics by both sides, the Chinese as in 1938 Yellow River flood and later by the Japanese with the Three Alls Policy, "kill all, burn all, loot all", initiated in 1940, claimed millions of lives. The Chinese nationalists resorted to massive civilian guerrilla tactics, which fatigued and frustrated Japanese forces. Countless Chinese civilians were executed on the suspicion of being resistance fighters. Japanese war crimes at Nanking and other sites in China and Manchukuo have been well documented.