 Militia groups known as the People's Security Body (BKR) were formed and Amirmachmud headed one in Lembang, West Java.In 1946, after the People's Security Army (TKR) had been established, the Lembang BKR was integrated into Kodam VI/Siliwangi (Siliwangi Division), a military regional command responsible for the security of West Java.Amirmachmud was then transferred to North Bandung, where he led his troops in battles against British troops and Dutch troops, who were eager to retain their colonial empire.