Timeline

• December 1969, the elections held after political parties had been re-established in Pakistan emphasized a growing rift between east and west. In West Pakistan, Zulfikar Ali Bhutto and the Pakistan People's Party emerged victorious; in the east 160 of 162 seats were won by the Awami League led by Sheikh Mujibur Rahman. The League wanted complete internal autonomy for Bangladesh with a central Pakistan government controlling foreign affairs and defense.
  
• 25 March 1971, Pakistan's president Yahya Khan declared a state of emergency in East Pakistan. Sheikh Rahman and other leaders of the Awami League were arrested, while Pakistani troops began a brutal suppression.
  
• 14 April 1971, the leaders of the Awami league, in refuge in India, declared Bangladesh to be independent.
  
• 21 November 1971, Indian troops clashed with Pakistani forces in Bengal as Indians crossed the border.
  
• 3 December 1971, Pakistan attacked Indian air bases.
  
• 4 December 1971, India invaded Pakistan.
  
• 17 December 1971, Pakistan accepted cease-fire terms.
  
• 12 January 1972, Mujibur Rahman became prime minister of Bangladesh.
  
• 3 July 1972, peace terms agreed between India and Pakistan at Simla.
  
• February 1974, Bangladesh independence recognized by Pakistan.
  
• 15 August 1975, Rahman killed in military coup.
  
• 1977, General Ziaur Rahman assumed the presidency (assassinated in 1981).

there were group in Bangladesh during this time called the freedom fighters that were retaliating agents the government

Statistics of the Freedom Fighters:
The total number of Freedom Fighters during Bangladesh War of Liberation was not recorded anywhere.

The number of people that died in this war is not known very well. Pakistan says only 30,000 people died. India and Bangladesh say that nearly 3 million were killed.

It all started with Operation Searchlight, a planned military pacification carried out by the Pakistan Army started on 25 March, 1971 to curb the Bengali nationalist movement by taking control of the major cities on March 26, and then eliminating all opposition, political or military, within one month. Before the beginning of the operation, all foreign journalists were systematically deported from Bangladesh. The main phase of Operation Searchlight ended with the fall of the last major town in Bengali hands in mid May.