After the dark night of March 25 1971 the Bengali members of the Pakistan Army disassociated with the Pakistan Army and regrouped with students, political leaders, peasants and workers to form revolutionary forces. These groups were scattered all over Bangladesh and formed independently without any central command. On April 4 the top ranking Bengali officers met at Taliapara the temporary head quarter of Major Khaled Mosharraf. This was the first attempt to organize the Liberation War and Bangladesh was divided into 4 regions with a high-ranking officer as the Commanding Officer. Coln. (retd.) M. A. G. Osmani was made the head of this body.

The 4 regions and their Commanders were:

1.    Chittagong Region: Major Ziaur Rahman

2.    Comilla Region: Major Khaled Mosharraf

3.    Sylhet Region: Major Shafiullah 

4.    Jessore Region: Major Abu Osman Choudhury

After that it was redefined and sub-divided. On 11th July after a conference of the Army officers and the civil administration 11 sectors were formed and sector Commanders were appointed for effective operation against the Pakistan Army.

During our Liberation War Bangladesh was divided into11 sectors. Each Sector was headed by a Sector Commander and under him were (depending on the size) few sub-sector Commanders. There were regular forces (meaning Bengali members of the Pakistan Army who rebelled and joined the Liberation War) and the Guerrillas (peasants, students and others) in each of these units. Major Gen. M. A .G. Osmani was the Chief of Staff of the Liberation Forces.

MUKTI BAHINI (Freedom Fightters)

Sector 1:

(a) Area: The entire districts of Chittagong, Chittagong Hill Tracts and parts of Noakhali district (areas east of Muhuri river).

            (b) Number Of Sub-sectors: 5

             (c) Sector Troops: 2,100

            (d) Guerrillas: 20,000

Sector 2:

(a) Area: Eastern part of Faridpur district, southern part of Dhaka district including Dacca city, Comilla district (excluding areas north of Akhaura-Ashuganj rail line) and Noakhali district (excluding areas east of Muhuri river)
(b) Number Of Sub-sectors:6

(c) Sector Troops: 4000

(d) Guerrillas: 30000

Sector 3:

(a)     Area: Part of Comilla (areas north of Akhaura-Ashuganj rail line), part of Sylhet (areas south of Lakhai-Shaistaganj general line), northern part of Dhaka and Kishoreganj sub-division of Mymensingh district.

(b)     Number Of Sub-sectors: 10

(c)      Sector Troops: 2500

(d)      Guerrillas: 10000

Sector 4:

(a)     Area: Parts of Sylhet district as follows:
         i) Western boundary: General line Tamabil-Ajmiriganj-              Lakhai
         ii) Southern boundary: General line Lakhai-Shaistaganj
(b)    Number Of Sub-sectors:6

(c)     Sector Troops: 2000

(d)     Guerrillas: 8000

Sector 5:

(a)      Area: Rest of Sylhet district west of the general line Tamabil-Ajmiriganj.

(b)      Number Of Sub-sectors: 6

(c)     Sector Troops: 800

(d)     Guerrillas: 7000

Sector 6:

(a)        Area: Parts of districts of Rangpur and Dinajpur (areas west of the river Jamuna and north of general line Ranisankail-Pirganj-Birganj of Dinajpur and north and east of general line Pirganj-Palashbari in Rangpur).

(b)        Number Of Sub-sectors: 5

(c)        Sector Troops: 1200

(d)        Guerrillas: 6000

Sector 7:

(a)        Area: The entire districts of Rajshahi, Pabna and Bogra and parts of Dinajpur and Rangpur districts (areas south of general line Ranisankail-Pirganj-Birganj of Dinajpur and south and west of general line Pirganj-Palashbari in Rangpur).

(b)        Number Of Sub-sectors: 8

(c)        Sector Troops: 2000

(d)        Guerrillas: 10000

Sector 8:

(a)        Area: The entire districts of Kushtia and Jessore and parts of districts of Faridpur (excluding Madaripur sub-division) and Khulna (only Satkhira sub-dividion).

(b)        Number Of Sub-sectors: 7

(c)        Sector Troops : 2000

(d)        Guerrillas:  7000

Sector 9:

(a)        Area: The entire districts of Barisal and Patuakhali and parts of districts of Khulna (excluding Satkhira) and Faridpur (only Madaripur).

(b)        Number Of Sub-sectors: 8

(c)        Sector Troops: 700

(d)        Guerrillas: 10000

Sector 10:

(a)       Area: Entire Bangladesh

(b)       Number Of Sub-sectors: ---

(c)       Sector Troops: Naval Commanders

(d)      Guerrillas: -----

Note: The 10th Sector did not exist on ground. This sector comprised only the naval commandos. These naval commandos were sent in groups of different sizes to different sectors for commando actions targetting ships, watercrafts and navigational aids in the sea and river ports of Bangladesh. During operations, these groups would come under control of the sector commanders in whose areas the naval operations were to be conducted. On return from naval operations, these commandos would again belong to their original sector, i.e. No. 10 Sector.

Sector 11:

(a)        Area: The entire district of Tangail and parts of Mymensingh district (excluding Kishoreganj sub-division).

(b)        Number Of Sub-sectors: 8

(c)        Sector Troops: One Battalion

(d)        Guerrillas: 20000

Note: Z Force under Maj. Ziaur Rahman was located in No. 11 Sector area and operated in this sector. Later, during the final campaign, Z Force operated in Sylhet district.

A large number of freedom fighters operated independently under guerrilla leader Kader Siddiqui, carried out a series of actions against the Pakistanis.