 Ethnic Chinese residents arguably suffered the most brutal treatment, as the Imperial Japanese Army massacred thousands of Chinese as part of the "Sook Ching" campaign to rid what was perceived as anti-Japanese elements in the society.Penang's womenfolk were also coerced to work as comfort women by the Imperial Japanese Army.Penang's residents also had to endure economic hardship during the Japanese occupation, with hyperinflation caused by the oversupply of the Japanese-issued 'banana' dollars, and the acute shortage of food and raw materials, due to a combination of Japanese wartime rationing and an Allied blockade of Japanese shipping.