 When the war broke out, "IV corps" went into action in the Agartala sector.At the start of the Dhaka Campaign, Dhaka was set as an objective for "II Corps" and "IV Corps " had been tasked to capture the fortress of Comilla.By 8 December, troops of the "57 Mountain Division" and the "IV Corps" had already achieved their initial objectives of occupying the territory leading up to the Meghna.