Mukti Bahini forces numbered 30,000 regular soldiers (including 3 brigades containing 8 infantry battalions and 3 artillery batteries) and at least 100,000 guerrillas by December 1971.
Two gunboats under Indian officers and crewed by Bengali seamen were engaged in Operation Hotpants prior to 3 December 1971, harassing merchant traffic to East Pakistan and laying mines on the waterways.
Air Chief Marshal Pratap Chandra Lal formed an advance HQ at Fort William after consultation with Major General Jacob to coordinate operations with the army before the start of the war.
Western Sector: North East and North Western Sector: AOC-in-C: Air Vice Marshal Devasher HQ: Shillong CO: Flight Lieutenant Sultan Mahmud HQ: Dimapur, Nagaland, then Agartala This unit was formed by Bengali pilots and technicians defecting from the Pakistan Air Force.
Flying light aircraft donated by India, they launched attacks on depots and communication lines on 2 December 1971, before the start of the war.