IV Corps ( India ) The IV Corps is a military field formation of the Indian Army , created in 1961 . The IV Corps in the India Pakistan War 1971 . " Under the command of Lieutenant General Sagat Singh the IV Corps , with all eight East Bengal Regiment battalions , had already made some gains before the war . An enclave south of Akaura served as a springboard for 57 Division , which advanced along the rail line to Ashuganj . In seesaw fighting that saw several successful Pakistani counterattacks , 27 Brigade of the Pakistani 14th Infantry Division fell back across the Meghna River and destroyed part of the rail bridge , blocking immediate passage of the river . General Singh , however , saw Dacca as “ the final answer ” and decided “ to go beyond my assigned task . ” 62 In an impressive display of improvisation , IV Corps began crossing the broad Meghna on 9 December in a hastily assembled helicopter lift operation supplemented by every variety of local water craft . Pakistan ’ s 14 Division was no longer a hindrance as its 27 Brigade had retired to Bhairab Bazar and its other two brigades ( 202 and 313 ) were isolated at Sylhet . " " Further south , the Indian 23rd Infantry Division also reached the Meghna on 9 December , seizing both Daudkandi and Chandpur against light resistance . The isolated Pakistani force at Laksham capitulated the same day , leaving only the garrison of Mayanmati to offer organized resistance east of the Meghna . The Pakistani 39 Division had disintegrated . 65 A sense of imminent victory drove the Indians , and , as 57th Mountain Division painfully built up its strength west of the river , 23 Division ( shedding 83 Brigade and “ Kilo Force ” to push toward Chittagong ) , prepared to make its own improvised crossing . In another colorful , tenuous helicopter and boat operation , 301 Brigade landed at Baidya Bazar on 14 December and closed on the Lakhya the following day . " " India ’ s 57 Division was also advancing : 311 Brigade and “ Sierra Force ” were threatening Demra and 73 Brigade had reached the Balu east of Tungi . General Sagat Singh ’ s decision to “ go beyond his assigned task ” had paid off . The Indians were also approaching Dacca from the northwest , hindered more by severe logistics constraints than by the near - nonexistent Pakistani opposition . Indeed , Pakistani 93 Brigade , over the protest of its commander , had been withdrawn toward Dacca in a desperate attempt to shield the unprotected capital against the Indian troops advancing rapidly from the east and northeast . The Indian airborne drop of 2 Para at Tangail on 11 December accentuated the menace to Dacca . Although 2 Para ’ s appearance made only a marginal contribution to the tactical battle , it helped to unnerve Niazi and others in Eastern Command headquarters , already anxious because of the lack of regular combat troops in the capital . 68 Predations of the local Mukti Bahini under Qadir “ Tiger ” Siddiqi compounded Pakistan ’ s woes , disrupting movements and depleting morale . The Indian paratroopers joined hands with 95 Brigade on 12 December and , with 167 Brigade hastening up from Jamalpur , soon reached and crossed the Turag . " " By 15 December , the Pakistani situation around Dacca was hopeless : the lone brigade of 36 Division was broken , the newly arrived 314 Brigade was little more than a paper organization , 14 Division was sitting demoralized and useless at Bhairab Bazar , and 39 Division had ceased to exist . On the morning of 16 December , Major General Mohammed Jamshed Khan drove out of Dacca to arrange the cease - fire . " Composition . In 1961 , IV Corps , which had been disbanded within the British Indian Army after the Second World War , was reestablished . It currently consists of : In addition , as of mid - 2010 , an additional mountain division appears to be forming , reportedly to be attached to this corps , located in Assam . It has been confirmed as being 71 Mountain Division .