<P> On 16 December 1971, Lt. Gen Amir Abdullah Khan Niazi, CO of Pakistan Army forces located in East Pakistan signed the Instrument of Surrender . At the time of surrender only a few countries had provided diplomatic recognition to the new nation . Over 93,000 Pakistani troops surrendered to the Indian forces & Bangladesh Liberation forces, making it the largest surrender since World War II, although the Pakistani Army had fought gallantly according to Indian Army Chief Sam Manekshaw . Bangladesh sought admission in the UN with most voting in its favour, but China vetoed this as Pakistan was its key ally . The United States, also a key ally of Pakistan, was one of the last nations to accord Bangladesh recognition . To ensure a smooth transition, in 1972 the Simla Agreement was signed between India and Pakistan . The treaty ensured that Pakistan recognised the independence of Bangladesh in exchange for the return of the Pakistani PoWs . India treated all the PoWs in strict accordance with the Geneva Convention, rule 1925 . It released more than 93,000 Pakistani PoWs in five months . Further, as a gesture of goodwill, nearly 200 soldiers who were sought for war crimes by Bengalis were also pardoned by India . The accord also gave back 13,000 km (5,019 sq mi) of land that Indian troops had seized in West Pakistan during the war, though India retained a few strategic areas; most notably Kargil (which would in turn again be the focal point for a war between the two nations in 1999). This was done as a measure of promoting "lasting peace" and was acknowledged by many observers as a sign of maturity by India . However, some in India felt that the treaty had been too lenient to Bhutto, who had pleaded for leniency, arguing that the fragile democracy in Pakistan would crumble if the accord was perceived as being overly harsh by Pakistanis . </P> <P> Reaction to the defeat and dismemberment of half the nation was a shocking loss to top military and civilians alike . Few had expected that they would lose the formal war in under a fortnight, and there was also unsettlement over what was perceived as a meek surrender of the army in East Pakistan . Yahya Khan's dictatorship collapsed and gave way to Bhutto, who took the opportunity to rise to power . General Niazi, who surrendered along with 93,000 troops, was viewed with suspicion and contempt upon his return to Pakistan . He was shunned and branded a traitor . The war also exposed the shortcomings of Pakistan's declared strategic doctrine that the "defence of East Pakistan lay in West Pakistan". </P> <P> During the war there were widespread killings and other atrocities--including the displacement of civilians in Bangladesh (East Pakistan at the time) and widespread violations of human rights began with the start of Operation Searchlight on 25 March 1971 . Members of the Pakistani military and supporting Islamist militias from Jamaat e Islami killed an estimated 300,000 to 3,000,000 people and raped between 200,000 and 400,000 Bangladeshi women in a systematic campaign of genocidal rape . Some Islamic clerics issued fatwas in support of raping Bengali women, especially Hindu women, as they considered the conflict a holy war . During the war, a fatwa in Pakistan declared that the Bengali freedom fighters were Hindus and that their women could be taken as "the booty of war". </P> <P> A large section of the intellectual community of Bangladesh were murdered, mostly by the Al - Shams and Al - Badr forces, at the instruction of the Pakistani Army . Just two days before the surrender, on 14 December 1971, Pakistan Army and Razakar militia (local collaborators) picked up at least 100 physicians, professors, writers and engineers in Dacca, and murdered them, leaving the dead bodies in a mass grave . </P>

Who headed the indian army in 1971 bangladesh war