[2] The army's actions so enraged some Bengali military officers that they revolted and joined the Bangladesh Liberation War.

At the end of June, considering the need of regular brigades to intensify the war against the Pakistan Army, the Provisional Government of Bangladesh decided to form three brigades under the leadership of Majors Ziaur Rahman, Khaled Mosharraf and Shafiullah.

Shafiullah, once the second-in-command of the 2nd East Bengal Regiment, was given the mission of organizing a brigade in September 1971.

[4] Shafiullah reorganized the two battalions of freedom fighters he had with him who were fighting in sector 3 to form a brigade that is popularly known as S Force.

It operated in Akhaura, Mukundpur, Dharmaghar and many other places from the end of November until the independence of Bangladesh was achieved.