During the Second Sino-Japanese War, the Communist Party set up the Hong Kong Office of the Eighth Route Army which engaged in united front works and raising funds disguised as the Yue Hwa Company. The Chinese Seamen's Union also organised a resistance movement by recruiting volunteers to cross over to Guangdong and wage a guerrilla war behind Japanese lines led by Zeng Sheng. There were also the Huizhou-Bao'an People's Anti-Japanese Guerrilla Force and the Dongguan-Bao'an-Huizhou People's Anti-Japanese Guerrilla Force militias which were formed in 1938. Commanded by Cai Guoliang, the guerrillas began operations in 1941 before the Japanese invasion of Hong Kong. On 2 December 1943, the Chinese Communist Party Central Committee regrouped the five guerrilla fighting units within the Pearl River Delta into the East River Column directly under Communist command. By 1943, the East River guerrillas had the total strength of about 5,000 full-time soldiers, who were divided into six detachments.