After the postponing of the session National Assembly of Pakistan, the High Command was authorised by the Yahya administration to launch the military operation (codename: "Searchlight" and "Barisal") in March 1971 in a view of curbing political opposition instigated by the Awami League– which had won majority in the 1970 elections and would have formed next civilian government of Pakistan had the army not intervened. The Pakistani Armed Forces launched Operation Searchlight on 25 March 1971 in a bid to take control of East Pakistan and subdue all resistance (political or otherwise) against the West Pakistani authorities. By mid of May, the Pakistan Authorities in East Pakistan, with the crucial support provided by the Pakistani military, had been in control of maintaining the writ of government in major areas of East, and the Mukti Bahini, under attack from Pakistan Air force and armed military units, started to retreat across the border into India.&lt;ref name="Dacca p. 36/37"&gt;"Surrender at Dacca: Birth of A Nation", Jacob, Lt. Gen. J. F. R., p. 36/37&lt;/ref&gt; By the middle of June, Pakistani army had driven the remnants of Bengali army and Para-military units, who had been supported by the civilians, across the border into India. The Mukti Bahini, formed around the defecting Bengali soldiers with civilian volunteers, started a guerrilla campaign.