Between 1937 and 1945 the Japanese Imperial Army formed 126 Independent Mixed Brigades (numbered 1–136 with some gaps), typically composed of various units detached from other formations. Some were composed of separate, independent assets (usually Independent Infantry Battalions). These brigades were task organized under unified command and were normally used in support roles, as security, force protection, POW and internment camp guards and labor in occupied territories. An Independent Mixed Brigade had between 5,000 and 11,000 troops.