East Pakistan signs the instrument of surrender to Indian army
The Bangladesh Liberation War was an armed conflict pitting West Pakistan against East Pakistan (two halves of one country) and India, that resulted in the secession of East Pakistan as the independent nation of Bangladesh. The war broke out on 26 March 1971 as army units directed by West Pakistan launched a military operation in East Pakistan against Bengali civilians, students, intelligentsia, and armed personnel who were demanding separation from West Pakistan. Members of the East Bengal Regiment, East Pakistan Rifles, East Pakistan police and other Bengali military and paramilitary forces, and armed civilians revolted to form guerilla groups and forces (generally termed as the Mukti Bahini) to fight against the army of West Pakistan. During the following months, India provided economic, military and diplomatic support to the Mukti Bahini in East Pakistan. On December 3, 1971, (West) Pakistan launched a pre-emptive attack on the western border of India, which marked the commencement of the Indo-Pakistani War of 1971. Finally, on December 16, 1971, the allied forces of the Indian army and the Mukti Bahini (Bangladesh Liberation Army) decisively defeated the (West) Pakistani forces deployed in the East resulting in the largest surrender, in terms of the number of POWs, since World War II.