of chemical weapons in China. For example, during the Battle of Wuhan from August to October 1938, the Emperor authorized the use of toxic gas on 375 separate occasions, despite the 1899 Hague Declaration IV, 2 – Declaration on the Use of Projectiles the Object of Which is the Diffusion of Asphyxiating or Deleterious Gases and Article 23 (a) of the 1907 Hague Convention IV – The Laws and Customs of War on Land. A resolution adopted by the League of Nations on 14 May condemned the use of poison gas by Japan. According to Prince Mikasa, a member of the imperial family of Japan, he watched an army film that showed Japanese troops gassing Chinese prisoners who were tied to stakes. Another example is the Battle of Yichang in October 1941, during which the 19th Artillery Regiment helped the 13th Brigade of the IJA 11th Army by launching 1,000 yellow gas shells and 1,500 red gas shells at the Chinese National Revolutionary Army. The area was crowded with Chinese civilians unable to evacuate. Some 3,000 Chinese soldiers were in the area and 1,600 were affected. The Japanese report stated that "the effect of gas seems considerable". In 2004, Yoshimi and Yuki Tanaka discovered in the Australian National Archives documents showing that cyanide gas was tested on Australian and Dutch prisoners in November 1944 on Kai Islands (Indonesia). In 2004, Yoshimi Yoshiaki published the most comprehensive study of Japan's military use of poisonous gas in China and also in Southeast Asia. Yoshimi discovered a battle report from a Japanese Infantry Brigade that detailed the use of mustard gas in a major operation against the Communist-led Eighth Route Army in Shanxi Province in the winter of 1942. The unit carrying out the operation noted its severity, and commented on the anti-Japanese sentiment among the civilian population affected. Torture of prisoners of war Japanese imperial forces employed widespread use of torture on prisoners, usually in an effort to gather military intelligence quickly. Tortured prisoners were often later executed. A former Japanese Army officer who served in China, Uno Shintaro, stated: The effectiveness of torture might also have been counterproductive to Japan's war effort. After the atomic bombing of Hiroshima during World War II, the Japanese secret police tortured a captured American P-51 fighter pilot named Marcus McDilda to discover how many atomic bombs the Allies had and what the future targets were.