During the Indo-Pakistani War of 1971 for the liberation of Bangladesh, when Pakistan Army created the 91st "ad hoc" brigade as part of the 39th Division to hold on to this area and to defend north of Chittagong, but these "ad hoc" formations lacked the staff and equipment of regular formations. Pakistan Army's 93,000 troops unconditionally surrendered to the Indian Army and India's local ally Mukti Bahini on 16 December 1971. This day and event is commemorated as the Bijoy Dibos () in Bangladesh and Vijay Diwas in India.